Old school way to attend a conference: Go to a new place and meet a bunch of new and stimulating people. Maybe you are a stimulating person yourself. Get exposed to a bunch of new and stimulating ideas. Go home and try to share what you learned and stay in touch with the people you met. Assimilate back into daily life, weeks later remember a really cool resource you found at the conference but can't find it. Try to apply what you learned but struggle along by yourself.
New school way to attend a conference: Go ahead and be stimulating and new, that part didn't change. Build a shared resource with other conference attendees, share pictures, links and heck even tweets. If you really get carried away you could even live blog the event. *Phew* tired yet? Personally I'd still like to see a Facebook or LinkedIn group related to the event so I can network with attendees after the event. That would be pure sweetness.
Oh yeah, and after the conference don't forget to get feedback using an online survey tool.