Here's my favorite pickoff move. I've said it before but I'll repeat it, its called the daylights play. The shortstop gives the signal, a full glove out, or the second baseman its more obvious but a full hand out towards second base. The pitcher turns towards the plate takes a breath then spins over to second as the middle infielder sprints to the base. I recently saw Pedro Martinez pick someone off like this, they were called safe but the replays showed he was out. Second baseman went over on a dead sprint and Pedro spun and wham!
Now your probably thinking oh the sprint is a dead giveaway, well no not really. It can help you. Once you do this its guranteed to be a close play. Now every time you run a full sprint at the base the coach is going to yell back or watch it or something. I do it all the time at shortstop I'll run at a full sprint and the kid takes a step back being cautious of the spin move from the mound.
My coach taught me this move and he said he picked the first kid off almost every game at 2nd then he said "I got to college and tried this, the kid was standing on the base waiting for me."
Haha its a good move though, kids don't see the spin on second a lot.
Disclaimer: a good third base coach will notice the sprint right away and give it away. But...if your clever enough you will already have sprinted there a few times when the pitcher isn't even looking at the base. Try it.