I've been using twitter client Mauku for a while now, and wished that there was a similar program for identi.ca. I've found one called Heybuddy at http://www.jezra.net/blog/heybuddy_identica_client
I have it up and running on my N800 and it works great. I've also just installed it on my Ubuntu desktop as well.
edit: here's the link to the heybuddy launchpad page