It's a free app that i found in the "Featured Apps" section of the App Store.
It uses the GPS and accelerometer to track your speed, longitude/latitude, time you are stopped/moving, etc. You just press start when you are ready to go and then when you are done you press stop and it uploads the data to your account on their website. You can choose to make the data public or private. Then you get an email with your track info and a link like this. This is my commute this morning...
https://www.trailguru.com/wiki/index.php/Track:11Z3

Yesterday was the first time i used it and it didn't work well, it had trouble tracking. But this morning it was spot on and worked perfectly.

That's Awesome!

sweet!

Awesome! Thanks for sharing.

Another thing that's amazing but probably hard to tell unless you are familiar with those roads, it even tracks the tiniest little turns, even the turn into my driveway at my office which is only about 20 feet from the street!

wished this worked with my non 3g phone.

I had installed that app last night, but forgot to set it up for my ride this morning... Was wondering how well it worked. If I remember this evening, I'll track my ride home and let you guys know about it...!

I can't wait to try this. Did it work ok with the iPhone in your pocket or do you have it mounted to the bike somehow?

Both days I had it in a fully enclosed neoprene case and then inside of my canvas handlebar bag. This is why I thought it didn't work the first day, but it worked fine today. It doesn't really need to be in the case, i just used it the first day because I had some other stuff in the handlebar bag that I didn't want scratching the iphone.

if it only works in the foreground does that mean you have to keep touching the screen to keep it from going to sleep? does it continue to work if you hit the power/sleep button without closing the app by hitting the home button?

You can keep it from going to sleep by going into Settings -> General -> Auto-Lock and setting it to Never.

Save further drain on the battery by switching off 3G, push notification, and Wi-Fi, turning down the screen brightness, etc.

That's what I figured. Too much effort. I'll wait for the TomTom solution which supposedly will address these issues.

It's not much effort; I usually have 3G, push, and wi-fi all turned off anyway.

No, it stays up and continues to work. No worries about it going to sleep. There was no need to set any special preferences or anything.

Cool, even simpler.

It'd be nice if it recorded the percent of grades one is riding...

Yeah I'd like this, but alas I'm a 1st gen user, so no GPS for me.

And as far as using another device (TomTom was mentioned), last thing I want on the bike is more stuff. Nice thing of the iPhone is it's all inclusive.

I too have been using Trailguru for a few days. Clever. I also turn off WIFI, Auto Lock and Bluetooth. iPhone will try to grab every wifi station on the road as you pass into range so it probably taxes the iPhone a bit there.

I play tunes in the background while Trailguru is running foreground and it works. I have a Belkin sports band to carry the iPhone on my arm. Works ok (not so good for skinny arms). I just put the phone into the carrier upside down so the speaker is pointing up and out of the pocket. I can easily hear cars and other road noise with the tunes playing. Did I mention I don't use ear buds. Have enough trouble with my ears as it is.

There are a couple other iPhone apps out there that I have installed on the iPhone. GoLearn Cycling and TrackThing. GL Cycling I use to record my miles and times on. Yeah I know it's manual entry but for now it is ok. I am waiting for an update to be able to export out of the iPhone to my Mac. It is meant more for someone just learning some things about bikes. Not recommended for experienced riders as you have to wade through several screens to get to the tracking log.

I have not used TrackThing yet but that is next to be tested.

Trailguru is clever but sometimes incredibly inaccurate. One of my Max Speeds this week was 149 KPH. Sweet! No wish for that to be true but seriously I am just getting back into shape as a a commuter on a very short commute to the Shuttle Bus stop nearby. I am not a long distance rider yet but am working my way up there very slowly. The Altitude/Elevation display in Trailguru is interesting. I knew I was struggling up hills and wanted to see the numbers. There is no percent grade though just feet or meter changes. I would love to know that information before I go out and discover a huge hill on the route. Being a little new to this and not yet in the best of shape I dread hills but am getting better with them.

One nice feature about the trailguru.com website are the topo maps. The maps are detailed so you can see terrain changes. YMMV with trailguru. So far it's been enlightening.

I also tested RunKeeper. Handy but not as accurate as my bike computer (none of the iPhone apps are close to the bike computer for accuracy).

There is a way to alter the number of data points the GPS picks up.

I reloaded iTrail which has an option to alter the GPS interval. I am not entirely sure if this sets GPS to that interval for all app's or just iTrail. When I was first testing iTrail I was having issues with it quiting. Now that I think that issue is resolved I will try it again. Anyway there are lots of apps for the iPhone. Some work well in some ways others in other ways. No one app does it all.

I doubt seriously there will be a HRM or cadence recording to go with these apps as it would probably require too many things running at the same time? Guessing on that bit. There are likely to be some serious programming challenges for all the functions everyone wants to squeeze into the iPhone for cycling. For now I am still in experimenting phase. If I can get this to work that will mean I only have to carry one thing instead of all the gadgets. I can dream.

I tried it again this morning.
Yesterday my mileage was 11.44 and today it was 11.37.
For me, that's close enough and depending on how much bobbing and weaving i do it could be spot on.
I can't really say if it's more or less accurate than my cyclometer but I never do fully trust those things because it relies on YOU to input the correct tire circumference. There just too much room for error there for it to be accurate. Even varying air pressure can make a difference in rolling circumference. I trust gps a lot more. I need to get ahold of a small gps that I can use to compare with trailguru.
One thing I did notice that was quite different between the two days was Max Elevation and both Total Ascent/Total Descent. Min Elevation was the exact same.

Hit the top of a hill fast enough and you gain a little air.

I've used the app twice. I'm a newb and I think its great app that needs a few bugs worked out. Here's what I did yesterday. Only problem is that I never hit 52mph like it reports. I think my max was about 35mph. https://www.trailguru.com/wiki/index.php/Track:13YM

Used it this morning on my 1st gen iPhone with no problems. Mapped out my ride perfectly. I was impressed.

Did it manage that just with the triangulation from cell towers?

I have been retesting iTrail and Trailrunner.

iTrail will record the data and can be exported to the Trailrunner site for further analysis.

Trailrunner does percent grades. Which is helpful.

Only gripe with iTrail right now is default quick start does not record data for posting. Have to remember to hit New Trails for it to record and post. Foggy brain in the morning and I forgot again and missed my data recording.

The iTrail developer is really very nice and helpful. He has plans to grow this application and is working with the Trailrunner developer. Both are nice applications.

https://trailrunnerx.com/ and of course is MacOS X only. will import several different formats which extends it's utility beyond just iTrail.

Is it posted on Trailguru? I'm just wondering how it worked w/ the 1st gen Iphone.

It's private. I'll do a public one for my route home and post the link here.