I seen a very pretty iridescent one, but I couldn't think of a use for it... Maybe turn them upside down somehow and made a windchime? They are pretty fragile some of them.
Might make a good cave for a fish tank, the neat colored ones, but I don't know if the paint is safe for fish.
This type of globe. They are every where and I just can't think of a use for them. I thought about placing them end to end but what would it become? They are clear & frosted but I can't think of how to use them. You could put a pump inside the large end and have a fountain if there were a base/bowl but I don't think that would look very nice - junky I guess.