Hell ya! I just picked up one of these last night (from Le Baron):
http://www.walmart.com/catalog/produ...uct_id=4791009
And it's great! Very easy to quickly zero your guns, be it red dot sight, rifle scope, even iron sights. Not only that, but you can see where the BBs will land (as I knew already, Glocks tend to hit about 4" low at 30ft, and the bore sight proved that) so it helps you with learning shot placement for various guns. Heck, I found that my TM MK23 springer with it's fixed sights is about an inch to the left.
Well worth the investment if you work on guns (part of my service with gun work is zeroing the client's gun in), or have a lot of guns that require the occasional re-zero.