Hey,
I don't know your budget, but I would look into the personalized M&Ms. If you can afford some, that would be something to start the talk and they'll remember. (plus - it's CHOCOLATE!!! How can you go wrong with chocolate?)
http://www.mymms.com
I'll read actual post and replies later and add my 2 cents. I saw the topic title and then saw the commercial. I'll be back with more ideas for sure that are more tradeshow-esque!
Cortney