Tweetdeck is a very powerful twitter client which is written in the rather nifty Adobe Air framework. Unfortunately the air platform does not yet have support for 64-bit Linux. I imagine it will come along once flash 10 for 64 bit Linux comes out of beta. There is a rather long tutorial on how to work around the limitations and run it in 32-bit mode on 64-bit linux right here but that isnâ€™t enough to run tweetdeck. Youâ€™ll also need to pull down a copy of 32 bit libgnome-keyring to allow it to access your keyring.
ar x libgnome-keyring02.22.2-0ubuntu1i386.deb data.tar.gz
tar -xzvf data.tar.gz
cp usr/lib/* /usr/lib32/