check this isntrument, the guy plays it very bad but the sound is amazing:

http://www.youtube.com/watch?v=J-99jwGFWos&feature=related

is there any music you know with this instrument?

The drummer from Rush, Neil Peart, used the glockenspiel in some of their older recordings, but usually to add atmosphere to a track. He still uses it for his drum solos in concert.

I'm sure there are some classical pieces that use it, but I have no idea which.

There are many, but very rarely as a soloist or main instrument. For works that include small parts for the glockenspiel, here is a list:
http://vsl.co.at/en/70/3196/3204/3208/5769.vsl

This Mozart's "Die Zauberflöte" aria includes a part for glockenspiel (ignore the music box the guy is apparently playing -is just scenic atrezzo):

http://uk.youtube.com/watch?v=ElZcW4olcyA&feature=related

Other glockenspielers include Terry Cox with Pentangle and the percussion player (name escapes me, Jamie something) in mid 70s King Crimson, plus some early 70s Jethro Tull (Presumably Clive Bunker playing) such as Thick As A Brick.