I've worked on steering our Optical Tweezers instrument using Acousto Optical Deflectors. Here's an example of what it can do. We're trapping four 1 um silica microspheres in water using a single 1064nm laser that is time shared between the beads (it hops between them at a fast rate). Then we can program the AODs to steer the beads around in whatever patterns we want.
Looks like there aren't that many optical tweezers videos on youtube or google video yet, but if you thought this one was fun then check out this one too: http://www.youtube.com/watch?v=jCdnBmQZ6_s
This was done by Joost van Mameren who has a pong game implementation too on his page at http://www.nat.vu.nl/~joost/
Looks great!
Best wishes from Vilnius;-)