hmm, my bf and I get drinks, have a smoke, talk about what happened so far, check out the schedule for what's coming up, and sometimes just sit and read comics we just bought, or admire new toys.
I find myself constantly going over the schedule when I have a free moment, because I need to decide what to do next.
Funny you say photo scavenger hunt and stuff. One of my fave cons actually does various scavenger hunts. There's a photo one, but they also do a Stargate one, and a horror pop culture one. You pick up the list of stuff from a desk near the front of the hotel, and over the weekend, they gradually add the things on the list to con area. the SG hunt is for the constellations and sigils from the show, which are printed on little squares of laminated paper. They stick them all over the hotel, like under stairs, on pay phones, and other random places, and you run around looking for them and writing down the code on your piece of paper. First one to be most complete wins a little prize on Sunday. It sort of encourages you to stay all weekend.