been using the iPad to have people 'check in' to a demo at the past few live events we've run. So far it's working great. Our basic set up is to set up an event for the demo and when a person vists the booth for said demo we collect their info and check them into the event.
One 'hiccup' we encountered is that the latest event we attended provided a list of attendee's minus email addresses (don't ask, it's a strange situation) I was able to import the list into the event with out issue but on site when you try to sync the members with no email it doesn't work. It spins like it is syncing then displays the unchecked in count on the sync button. There was no error saying "leads have no email" or anything like that (wish there was)