Simple, Money, the people will love you for it.
LoL. Seriously.
-Stress Balls are very cool.
-Frisbees too.
-I would also like to see large blow up weapons with the logo's printed. (We WOULD have had large swords (4 feet!) but some one forgot to order them. I wont say who.)
-Playing Cards with Logo on back is a great idea.
-Battle type card game with pictures of the last year(s) robots for the kids. The game would probably be similar to LOTR or Magic The Gathering. 1 starter deck : Free. Memories and somthing to do on the bus ride home : Priceless.
-CD Roms are a great idea.
-Also if many many/all regionals would archive matches. Then a DVD of the competition up to Nationals would be great.
-Silly Puddy 'nuff said. The logo on the egg of corse.

-Bumper Stickers with familliar FIRST stuff. "For Instpiration and Recognition of Science and Technology." And other cool stuff.
-T-SHIRTS! Free T-Shirts rule! It gives people something to wear to school on the first day back from competition.
-Kissing Booth! Get your cutest and hottest members and have them hand out Kisses (Chocolate of corse) to people who come up.
-REALLY Big Smiley Face Beach Balls with logo on back. w00t
-CAMERAS Like the FIRST cameras given to the Refs and VIPs at some of the Regionals this year. FIRST logo and Your Team Logo.
-Batteries! You know how many CD players are brought to each trip.
-Bottled Water with FIRST/Your logo. (like last year at Nats.

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-And lastly FOOD! Every one LOVES Food. Fruit, Candy what ever. Food is the best.