sorry, but blog software and the very idea of blogs annoys the shit out of me. and besides...
the idea of blogging software is to make it easy and trouble-free to update your blog that nobody reads, not make it extremely painful to enter text via on-screen keyboard, or somewhat painful messing around with usb host adaptors and keyboards, then mess around some more with with usb networking and actually getting the gp2x online, so that it can finally post your arduously-written blog entry to the internet, via the computer it's plugged into
mobile blogging is something best left to pdas with wifi, or smartphones with internet connections, or at the absolute most bulky, a laptop
if you want to RUN a wiki on gp2x, you'd just need to get mysql running, the unit already has a php-capable webserver