TimeSleuth - a system for recording the amount of time spent performing activities such as consulting, project work, etc., and producing useful reports such as time sheets and summaries from the recorded data
Neote is a note taking application for mobile devices (specially written for Openmoko Neo Freerunner).
Its interface aims to be easy and finger friendly.
It's written in Python / Elementary and uses SQLite for storing data.
Notes can be organized using custom categories that you can add, rename and delete at any time
TMClock is Desk clock with Sliding Background Image which will make your Sharp Zaurus SL-5500 or SL-5600 PDA a sliding photo album with overlapped clock and calendar. You may choose clock and calendar layout as your taste