i've been playing with the iphone gps apps. why pay another $300 when i have one in my pack anyway? today's tour was the first test for the MotionX ($2.99) iphone application. the software is better than any gps i've ever used or seen. it tracked my route pretty well except when i was in thick trees, and it has us going down the south side of catherine a few hundred feet, which we did not do. i think it would be great with the exception of the iphone battery. when using the gps full time it dies quickly. i'd say it lasted 4-4.5hrs in the cold during today's backcountry ski tour. i am a map and compass guy. so when i thought about what i need from a gps it was just two things.
1) utm coordinates for the times when i feel like i need to cross reference on an actual paper map
2) waypoints for just in case situations like white outs
MotionX passed these two with flying colors and then some. i've even been uploading my gps files to Everytrail.com as you can see below. it's a pretty cool way to share the visual of the trip. you can even add geotagged photos to the map. which i've done.
as for the iphone battery issue i think i'll track the first 1/2 of my trips with the iphone, then shut it down or put it into airplane mode for the rest. that way i get a gps file of our route and have enough battery for utm reading and the emergency waypoint.