Heh, neat thread.
Ok, I'd first combine the DS, Nutter Butters, and part of that shirt together, and draw on it with the Sharpie to form a crude, somewhat disprotortioned human decoy. The snakes should (hopefully) attack this decoy, because it reeks of Nutter Butters and has a hideous shirt on. Then, I use the keychain to pry one of those parachute/seat cushion things off and jump out of the plane with it. Hope it works.
You're in a room that's roughly 20 feet cubed in dimension. All the walls are shatterproof, bulletproof one way mirrors with no windows or vents or cracks or the like, except there's a locked door of a similar material on one of the walls. It's hidden in a way that you can't figure out which wall it's on. You also happen to be tied to a chair (which isn't bolted to anything, and isn't particulary heavy, so it can move around the room with some effort). There's a wooden table in one corner with the following items that you can reach on it:
Deck of cards (1), missing the 8 of hearts for some reason
Can of Diet Pepsi (1)
Package of balloons (1, package contains 50 balloons)
Trout (1, also smells really bad)
Paper (15 sheets)
Packet of Markers (1, contains 16 markers, although only black, red, and yellow actually work)
Alarm clock (1, set to go off in about 10 minutes)
There's also a couple assorted rocks on the floor, but the way you're tied to the chair, you can't reach those in your current position. 'course, since the walls are shatterproof, you can't just throw them at the walls and expect them to break.
You hear footsteps, but can't glean from which side of the room they're coming from.
Your move, McGyver.