Just got one myself and its already working out great for the hobby with the gps and maps and emails. Had NCNS one day and was able to schedule a appt. real quick with the iphone.
Hell yeah the iPhone rules for hobbying. Also to add to the list it's easier to hide my ATFs numbers from the SO, of course browse the site to rereview the ad info before appts, reverse phone look ups for BP, use mirror app to make sure I have nothing in my teeth, play some slow sex music in the background, check my funds in the bank, and again that gps/maps is the best helper.
Hmm as much as an app for ECCIE be great for hobbyists, I don't think it would clear Apple's rules on which apps are allowed on the App Store. The best thing we could hope for is having the site formated for mobile use