Hmm what mouse drivers should I be using for this? USB mouse lights up on connect and what not, but doesn't appear to react in any applications I try?

Solved it: Qole's Bluetooth package seems to have done the job:
http://talk.maemo.org/showthread.php?t=58258

apt-get install bt-hid-scripts

Now just sync up and run showmouse in xterm. Gives you a nice little mouse cursor on the screen. Packages also map all the additional buttons for keyboard.