Well, assuming you have absolutely no ideas so far...
Have a look at the "Luce" design by a talented CPF member. I'm particularly fond of
this one.
Haven't seen many other applications, although I think they may be used in "map readers" which are sometimes available in B@rt's group buys. There are also plastic-bodied "torches" which obviously use them. Here is the latest group buy thread:
http://www.cpfmarketplace.com/mp/showthread.php?t=187523
You may already be aware of these applications, but this is all I know of.
As for mounting, I've seen neoprene used as an effective shock absorber. A low shrinkage adhesive can be used to glue or encapsulate small vials, and I imagine that would work with spheres as well. The preferred encapsulant seems to be Norland 61 optical adhesive - clear, colorless and durable. I guess the general rules for mounting seem to be
1) protect from shock (make sure it can't impact anything hard)
2) protect from impact (ideally, keep it recessed in whatever enclosure you're using).
Hope this helps.
