[mkautzm]

I don't mean to be coy and snide, but I bet they'd appreciate a raise if you think they are worth it. Kind of goes up against, 'Need to keep it cheap'. If money isn't an option, then as was mentioned, some honest, sincere and public acknowledgement of their work is a great way to thank them.

[jimcsharp]

I would find it hard not to be personally offended at being handed a sticker. If you're going to give a gift, make it booze. You know, adult stuff. Not kindergarten stuff.

Sincere public ack > sticker.