I configured and prepared packages of 3 programs to recognize gestures on the n900. May be useful to someone.

Gestikk (python) - it has assigned one gesture: "<". You can add own gestures but only on pc and then copy ~/.gestikk/gestures.conf to maemo. Be careful, one person after installing this had to do reflash

Wayv - it has assigned few gestures: CTRL + ^ - terminal, I - fullscreen, L - Flash with kmplayer. If you want more, see the /etc/wayv.conf and DEFAULT.wkey. Additionally it recognize tap/slide of the right edge of the screen like in Nemo and run taskmanager.

qt-slide - just move your finger from the left side of screen. CSSU-testing/thumb is necessary (maybe just CSSU-stable - not tested) and screenshot-tool. It does not work properly in fullscreen apps.