I don't know of any. You could simply save off cache web pages for reference (although viewing pages offline may require you to set up a fake wireless connection, since the browser always tries to go online). If you are using your Nokia tethered to a phone, then you can access cache pages directly, of course.

There are some general note-taking apps, like leafpad or Maemopad Plus (which has a tree-structure for its notes).

FBreader is a document viewer that can read Palm-format files, so it may be able to view the Geocaching.com automatic search files (which I think are .prc) although I haven't tested that.

Although you mention you don't need maps, Maemo mapper might be useful too. Even if you don't have a bluetooth GPS reciever, you can use it to download and browse aerial photo views, which might supplement your GPS map.