In all the bad press of Twitter lately, here is a good reason to use it. The Mars Phoenix Lander is Twittering. The Jet Propulsion Laboratory (JPL) set up the account to keep the legions of followers up to date. It not only gives updates but also answers questions about it’s interplanetary soil-digging device.
Of course, you can get all updates on the Phoenix Mars Lander Page but why not set it up into your account and follow the action via the Social IM network?