Went to see Blue Man Group at Lexington this weekend. Great show. These guys are always entertaining, a great blend of music and vaudeville performance. I've seen them three times so far and, though I prefer the original line-up of performers, the current set are still good in their own right.
The concert originally featured Venus Hum and Tracy Bonham. I strongly suggest picking up their original DVD, or catching it on PBS sometime, as both are stellar performers. Tracy really rocks out performing Baba O'Riley with her violin.
They've since changed out to a few new performers to fill those slots. The nice change is Mike Relm as opening act and providing some video work during the concert. Check out his YouTube page, or this performance to get an idea of what he does:
The Blue Men have always been good about using technology, and actively encourage people to use their cell phones during the concert. They've got an interactive text-message thing going on, and have people hold their cells up as lighters during certain songs. Plus, they encourage you to take pictures and post them on the BMG site (though most venues prevent you from taking "high quality" cameras inside).
So, short version: if you can see them, do it.