BiskitPnts made a request in the online forums for a WAP enabled site that lists caches. I had some "free time" this afternoon and played around with WML (wireless markup language).
The final result is www.geocaching.com/wap - if you have a wireless phone/device (I don't :), you can plug it in and always have your caches handy. If you're curious, there's an emulator at http://www.wap.com if you want to see what it looks like.
Like the site, you can search by Country, State, or Zipcode. Zipcode is the best (US only, of course), especially if you're travelling somewhere new and want to find out quickly how close a cache might be.