Paperless Geocaching
As you already may know, Kaddi and me love geocaching. We do this for little more than a half year and improved our equipment over the time. When we started, we created printouts for all caches we were out to search. This was a lot of paper which is bad for the environment and quite impractical as well. Today we use several tools to make our geocaching experience paperless and more easy as well.
Here are the tools we use:
Geocaching Greasemonkey Script
There were two flaws in the geocaching.com websites that made it harder to use than it should be. I fixed both by a little Greasemonkey script.
First there is not a waypoint lookup form at every page. So, when you're back home and want to log all your found (or not found) caches it sometimes needs an extra click back to the front page just to enter a new waypoint code. Because the site tends to be slow, this extra click is really annoying. The Greasemonkey script simply puts a lookup field in the top header of every page.
The same script also fixes another “too many clicks” problem: we use the print view very extensively (see below) but we always want to see all logs with the hints decrypted. The mentioned Greasemonkey script changes the print view link to do exactly that.
The script is available at userscripts.org
Plucker instead of Printouts
Plucker is a nice Open Source ebook reader for Palm powered PDAs. We use the Plucker Webinterface I wrote recently to convert the print view (with all logs and decrypted hints) to a Plucker file.
Because Geocaching.com shows coordinates to logged in users only, you need to login at their site first, and then use the “Pluck with Cookies” bookmarklet to create a plucker document.
This is not yet perfect. Some images seem not to work with the plucker interface and the UTF-8 conversion doesn't work as well, but the cache descriptions are still readable and usually enough to find the cache.
Palm tools
There are two more useful tools when caching with a Palm.
The first one is called Navigate. It is able to calculate the direction and distance between two coordinates and – even more importantly – it can give you the coordinate of a point calculated from distance, direction and current coordinates. The latter is a typical task for certain caches, where you arrive at a point and the description says “go 134 meters in 152° to find the final cache”. I'm sure certain GPS receivers can calculate the target coordinate with this info, but my NaviGPS can't, so this little tool is very valuable to us.
The second tool is even simpler. It just provides an easy way to decrypt ROT13 hints used by Geocaching.com to hide certain hints. It's called c1ph3r and can also translate from and to leet if you need it 
Of course a Palm can help you with many other cache related tasks as well. Eg. one cache used a periodic table to encrypt the final cache location. Using ChemTable was a big help in this case.