I have been happy with GeoBeagle on my Moto Droid, too, although the instructions for setting up the SMS textmark facility fail me. Specifically, the userid and pass that 41411 gives me is rejected when I follow the reg instructions here:
Using TextMarks for the first time
Send an SMS message "GEOC" to 41411
The response should give you a device identifier and pin to link to your Geocaching.com account.
Visit Geocaching.com and create an account (if you don't have one)
Visit your "my account" page and click on the "Access My Field Notes" link (on the right-hand side of the page)
Click on "Link Trimble's Geocache Navigator to your account." This is a general purpose link that works with SMS.
Enter in the device identifier from the SMS message and the pin provided to you to link to your account.
That's it! Any future SMS messages will work with your Groundspeak account on Geocaching.com
Source: Textmarks instructions from Coord.info
Thanks for any help getting me through the rejection at the "Link Trimble's Geocache Navigator" point.
Harold