Good question! First of all, time is ticking. Those leads are hot so you probably need to respond to them asap (ideally right after the Summit). Create a Smart List, start a campaign and thank them for stopping by your booth or your event. In addition, you might ask them if they interested in learning more about yorur company or if they want to receive a white paper. Basically, you want to get a sense of how interested they are in your company, your services.. and how interested are they in 'going Google' : ) . Since these are Sr. Level people, take a look at where they are located. If there is a cluster of folks in a specific city, you might want to consider hosting a lunch or some sort of event for them. Hope this helps.