You know those big LED signs that scroll dumb messages? Wouldn't it be cool to have one that you could hold?
That's what the Skyliner is. It's a little plastic chunk with a handle on one end and a vertical row of LEDs on the other. You program in a message or use one of the 15 or so included messages, and twirl it over your head. Your messages appears in in air as a surprisingly readable blur. It works the same way as those big message boards, except that it's only on column: Your spinning it spreads the message out into a message in the air. I've used mine to "cheer" for the local football team (who, BTW, are very poor.), to find my family in a huge crowd of people at Six Flags, and for dozens of random things like that. You can get them at http://www.theskyliner.com or at Spencer's Gifts. A great deal at ~$20.
The skyliner is made by Versatile Visions, Inc.