Clip-n-Seal is a super simple, useful and effective device. It's basically a bag clip, but is really easy to use and makes an airtight seal. Small enough to store in your kitchen drawer, they're a must for anyone obsessed with freshness. $5 per pack of 3.
Ryan McGinness. This one is filled with a lot more ‘tude, but is very funny if you have my sense of humor. $29 at Krudmart where there’s lots more good stuff.
Another throw back to the Sky Writer, LighTalk goes one step further. You can scan any image to then play it back by waving the pen back and forth to illuminate the LEDs. Passing notes in class will never be the same again. $42 at Compact Impact