I ran across the term crystallophone while researching the post 8 Weird and Wonderful Musical Instruments. According to Wikipedia, "A crystallophone is a musical instrument that produces sound from glass." There are quite a few different types, as you'll see in these videos.
Some Mozart, performed by Thomas Bloch.
Most of us just call this instrument "wine glasses", but if you play them with a wet finger around the rim, it's a glass harp.
When you tap them, it's a glockenspiel.
When you play them with a bow, it's a wine glass violin!
Glass can also be a wind instrument. Witness an awesome performance by the Bowen Beer Bottle Band.
This was a college project.
The instrument on the right is a verrophone, which is like a glass harp except built just for the purpose of music in a nice sturdy frame.
The Crystal Trio
This band plays all glass! The Crystal Trio has a glass harp, glass pan flute, and a verrophone.