To control your n8x0 using a wiimote you can use CWiid or XWii.
XWii is easiest to use since it does not require any messing with kernel modules but takes a lot of cpu resources (together with Xomap sometimes 50%).
CWiid is complex to use and on a n800 even harder since loading the required kernel modules (uinput and joydev) renders your N800 stylus keyboard useless. Using my version of the usb otg control might help. Check it here.
Both support using all wiimote buttons and a means to control the mouse using the accelerators or the IR pointer (I could not test this since do not have a sensor bar).
I packaged CWiid by building the current svn (r201) and adding scripts from 'yabbas'. The package can be downloaded here: cwiid_svn-r201-1_armel.deb. If you want here are the cwiid_svn-r201-1.tar.gz and cwiid_svn-r201-1_armel.changes.
See his forum post on internettablettalk for his explanation on how to use CWiid on maemo or check the CWiid homepage
I packaged XWii by building version 0.12. The package can be downloaded here: xwii_0.12-1_armel.deb. If you want here are the xwii_0.12-1.tar.gz and xwii_0.12-1_armel.changes.
Easiest way to start it is typing start_xwii.py in an xterm. It will ask which profile to use and then starts xwii. Check the XWii home page for more.
Last updated: 2009-08-22