I’ve temporarily added Wired’s Mars Lander Blog to the favorites category on my blogroll as they will be frequently posting updates on the mission’s progress.  The Phoenix Lander is scheduled to touch down late today (Sunday, 05/25) and begin its work.  NASA also has a project blog going but alas, no feed, so you have to go there to get NASA updates.

Update:  All along I had been thinking that this would be a great subject for Twitter updates if someone on the inside had the tool.  Sure enough, you can follow MarsPhoenix, which appears to be coming from inside NASA, and I also am following Spacelinks.net’s SpaceWire.  Also, if this kind of thing is of interest to you, NASA is on Twitter although they appear to be leaving the frequent Phoenix updates to MarsPhoenix.