There might be some light at the end of "No--proper-Twitter-Tool-for-N900"-Tunnel. An App written in Qt presented by 3 Guys: TweeGo (formaly known as TwitterBox).

TwitterBox is a twitter client developed for Maemo 5 using Qt/C++.

Combining great usability and excellent graphics, we managed to achieve an amazing user experience.

thanks to Simon from knownokia.ca who managed to install and test the early bird. this is an early Alpha, but looks good so far :-)

UPDATE:

TwitterBox was already in use, now it's TweeGo.

TweeGo is a twitter client developed for Maemo 5 using Qt/C++. Combining great usability and excellent graphics, we managed to achieve an amazing user experience. Souce Code: http://gitorious.org/tweego

Thanx to Rodrigo Ramos for the update.

Be careful: it's an ALPHA Version!!!

How to install TweeGo

1. download "qt-mobility-examples" in app manager
   (you need some Qt4 librairies, that are not included in package yet)
  

2. Download the latest version of tweego

3. Installation

start a X Terminal
sudo gainroot
if you saved it in Documents do:
cd MyDocs/.documents

dpkg -i tweego-0.1.deb

How to uninstall Twitterbox

start a X Terminal
sudo gainroot
apt-get remove tweego