Originally Posted by
joewein
An external battery will take care of the insufficient battery capacity of the iPhone and other smartphones. As I mentioned before, an USB battery powered my Android phone for over 20 hours. I keep it on the handlebar with a smartphone holder, always in sight, unless it's pouring down with rain (if it drizzles, I wrap it in cellophane). Google Maps does a great job showing me routes that I want to follow, uploaded as a KML.
If you already have a smartphone, a phone holder and a USB battery are much cheaper than even an entry level Garmin, let alone the 800.
Where the 800 makes sense is if you also want to record cadence and pulse, not just your speed and course.
As for the iPod, I can't think of many places where I would consider using headphones on a bicycle because they insulate you too much from your environment. I would not want to put myself and others around me in danger. The first two rules in our group rides are "wear a helmet" and "no headphones!"
Do you run into overheating issues with the iPhone? Especially after wrapping in cello? On warm days mine will shut down ... I had under the clear map cover on my front bag and figured there just wasn't enough air flow to keep it cool. However I've also run into that same issue on rides over ninety minutes with the phone not under the cover. Really curious to find out if it's just my phone and local conditions or if it's a persistent problem for everyone.