Please, please, please, please, PLEASE... if you have any shred of humanity in you...
DO NOT buy them bath towels!!!! When my husband and I got married in April, we got
at least a dozen sets...
Have you tried looking on
the Wedding Channel.com to see if they have put any of their wedding and/or registry info on their?
Also, you might think of giving them a $20-30 gift certificate to somewhere... a favorite/fancy restaurant, Target/Wal-mart, JC Penney's/Hecht's... I know that a gift certificate is a bit impersonal, but you can put it in a card and write a message that says "Instead of getting you yet another fondue pot, I decided to let you two pick out the gift... Congrats!" (or something along that line).
Hope this helps.
Nicole