Try MapMyRide for your iPhone, it's free. Since I use it to just let me know how long and how far I've ridden AFTER my ride it works for me. Of course YMMV.
How I do it is to just start the route tracking at the begining of the ride, and then let the display go off. You can bring it back if you want, to have a look at the map or stats. At the end of the ride, I save the route, it gets uploaded to my Mapmyride account. Then when you get to your computer, you can get all the stats you need, time, time splits by mile, a map of the route, elevation profile, avg speed. With the display off it's very easy on the battery.
You can even set it so that someelse can view your rides, even as you ride.
And it's free, just some small ads.
I use a biologic(the one that you see in BF adds), it is very sturdy, seem to be very water resitant, and you can used the touchscreen with it in the case.
And it's free, the app not the case..