Khweeteur is a great twitter and identi.ca client for Maemo. One feature I particularly like is its support for queuing of status updates, which is useful when connectivity is poor or non-existent (which, for me, is typically when something tweet-worthy happens). It also supports multiple accounts, e.g., a twitter account and an identi.ca account.
Khwetteur can automatically download updates and notify you when something happens. Enabling this option causes Khwetteur to periodically perform updates whenever there is an internet connection---whether it is a WiFi connection or via cellular. This is unfortunate for those, who like me, have limited data transfer budgets.
Deciding when to transfer updates is exactly what Woodchuck was designed for, and recently, I added Woodchuck support to Khweeteur. Now, if Woodchuck is found, Khweeteur will rely on it to determine when to schedule updates (of course, you can still manually force an update whenever you like!).
While modifying the code, I also made a few bug fixes and some small enhancements. Two improvements that, I think, are noteworthy are: displaying unread messages in a different color from read messages, and indicating when the last update attempt occured.
You can install the Woodchuck-enabled version of Khweeteur on your N900 using this installer. You'll also need to install the Woodchuck server, to profit from the Woodchuck support. Hopefully, the version in Maemo extras will be updated soon!