Not knowing what your preferences are, here are a few I'd like in various categories (in no particular order):
- Find application to search files and PIM data
- Search Home screen plug-in (with configurable search engine choices)
- Emerald Hunt for the Smartphone (using the d-pad instead of a stylus)
- MahJongg
- Internet tool suite (PING, TraceRoute, DNS lookup, NTP, etc.)
- Keyboard/button remapper
- System clock changer/tuner (like Pocket Hack Master)
- Smartphone benchmark tool
- Bluetooth sniping tool (needs to support Widcomm/Broadcom stack)
- Full function copy/paste utility (in all entry fields and Web pages)
- System database viewer/editor
Some of those may be out there, but I don't know of them (other than MahJongg).
Steve