I wouldn't expect to hand over anything more than a business card: I understand that you're talking about just a single page, but those single pages add up. I did hear of someone handing out a few flash-drives containing an extract of his work, which might be more welcome, but I'm not sure. I'd stick to a business card, and send the agent more after the event if invited to. Because if an agent is interested in seeing more they will ask for it, and if they're not, why force it on them?
Janet Reid advises writers to
always be prepared with materials when you go to conferences, but never, ever hand anything over unless asked. I always kept a copy of my query, synopsis, and first chapter hard copy in my bag, along with a CD with the entire manuscript, just in case. The CD ended up being a good thing for me, but I wouldn't have even mentioned I had it if he hadn't expressed interest.
I've never heard of a leave behind, but pictures are strongly discouraged in querying or submitting requested materials, so I'd leave that off anything I took to a conference.
Yup, I guess there's a first time for everything, but I've never had an agent or editor want to take anything from the conference, and I've made good conference contacts. Usually, if the agent or editor is interested, they've already noted my contact info and title, and their impressions, etc. So the take away would be irrelevant if they already were interested, and irrelevant if they weren't.
Now, if we're talking cold pitches, instead of pre-sent material, again, I think a business card with contact info and manuscript title and log line on back might be ok, if the agent asked for something - but again, agents and editors are professionals, they know how to write, and they all have methods for remembering the info about people they are interested in.
And it's the material, not the person, they'd be interested in. So, Monday after the conference, you send your requested material with a cover letter intended to spark their recollection - ie, "I enjoyed discussing my character Joe's motivations with you, and your comment X makes me think you would be particularly well-suited to represent my manuscript."
But, again, you can try it, but I've never seen it done and I'd feel uncomfortable with it.
~suki