You could try running an x-terminal, then running top in it (just type

top

then press enter.)

The program using the most CPU should be at the top of the list of processes you'll see. It updates at around 5 second intervals, I think

Edit: picture of what it should look like here: http://talk.maemo.org/showthread.php...549#post505549
+
google search which will find other info that might be of interest: http://www.google.com/search?hl=en&q...talk.maemo.org