At the fundraiser auctions I did as a portrait artist manager, we always had a table available to us in front of or beside our sample portrait (which we always brought lighting for so it was well-displayed). I would include the PR book on the table that I mentioned in the Business, Marketing and PR section:
http://forum.portraitartist.com/show...=&threadid=653
I also would put out a guest book. Guest books are a non-confrontational way for interested visitors to ask for more information or if you're busy talking with someone else, it's a way for them to leave information for further contact.
There's another point to this. We all tend to have a hard time tooting our own horn. Having another person at the table saying how great your work is can be a plus. Also, some people will talk to a rep before the artist because some have a consideration that if they talk to the artist they should buy something otherwise it's a insult. But, the artist should also be there because some people love to talk to the artist and don't have that consideration.