I still think the best app for general geocaching on a smart phone is CacheMate it can be found here
http://www.smittyware.com/ppc/cachemate/
and has a free trial where you are limited to 10 Caches in the database.The full version is only $8.It stores all of the geocache information and can give you distance and direction to a cache with a screen like most of the handheld GPS units.I dont really use it as much now that I have the new Garmin but I still reinstall it everytime I flash my phone.
if you have any questions feel free to contact me by email or the post I have several years experience geocaching and have used a pda for most of it
Also a lot of good information here
http://forums.groundspeak.com/GC/index.php?showforum=11
CrazyOn2Wheels