Ah children, there's a reason they're so cute...........It helps with
their survival. :-)

The glasses that the poster was thinking of earlier in the thread may
be Tervis Tumblers. (based out of Flordia I think) Really nice heavy
duty plastic glasses that don't sweat and look good. (no I don't work
for them) They come in a bunch of sizes and styles and are garaunteed
for life. (they back up that too, I've returned a few that the seal
went out of)

I think you're best option is the glass top, it's not too expensive
considering the time you put into the piece and it's pretty much fool
proof.........Though the quickest way to make a fool think is make it
proof against their last attack. :-)

Good luck!!!