I'm using Twitter plugin for Contacts and Conversations to twitter on my N900.
Twitter recently moved to OAuth. Problem is the Maemo package is outdated and seems to be unmaintained.
I ended up sitting down and writing a small python script that will re-route your HTTP requests to api.twitter.com after adding all the OAuth bills and whistles, read the reply from twitter and send it back. Neat ? :-)
There's also supertweet.net which I've discovered after I finished writing my script but seems they don't support all of the twitter API call while my script does that.
The script is simple without much error checking but it's been working for me for a few days already.
Last thing, I'm not interested in running a service like supertweet. I'll not be implementing the full OAuth protocol. Need to use it ? Register your own application.
git clone email@example.com:twitter-proxy/twitter-proxy.git
Next step: Thinking of maintaining the twitter plugin for Maemo. I already compiled the latest code and it sort of works fine :-)