I store a lot of info that needs to have encryption and KeePassX just didn't fit my free format needed to store the type of data I had. I started using NoteCase on my N810 & WinXP PC a few years back and it worked well. The notes are organized in a tree format with nested folders, so finding info is pretty quick if you build an organized tree.

Most internet site entries I store are along the lines of:
Site: http://www.foofoofoofoo.com
ID: foofoo
p/w: 42foo

but on the banking sites, I can also store with ease pass-phrases, Q&A's, and other security info. Having a note field allows it to be flexible for anything you need to store.

Since the Maemo 5 PR1.1 release, NoteCase compiled for Diablo works just fine on the N900. It can be found here with builds for Maemo, Linux, Macs, and Windows (runs on Win7 64bit fine too).

Screenshots from my device:




Issues:
1. No two way sync! I only modify records on my N900, then overwrite the file over to my PCs. This is an acceptable use case for me, but maybe not for you?
2. NoteCase in this form is a dead project, but is open source (see download link for src files). The continued development has been made in closed source and the evaluation version for $35 has lots of issues on the N900. With that said, I have yet to find a bug with the last open source version 1.9.8 and have been happy using it since its release.
3. Not optified (/usr/bin) and takes up 1.2MB.
4. Install package is a .deb file, so not newbie install friendly.
5. Not finger friendly. Non issue to pre-N900 Maemo users, but if you're expecting a finger friendly UI, this isn't it. Works perfectly with the stylus!
6. Lots of options and customization available. This is either a good thing or a bad thing depending on your perspective. If you really like to tweak settings, you'll love the options available. If you expect it to be pretty "out of the box", you'll be disappointed.
7. No templates or predefined entries. Again, can be good or bad depending on your perspective.


Hopefully this list doesn't scare off anyone from trying this very useful application. Please let me know if I can give any further information.