I was at a dealer show for Kinseys archery earlier this year and saw these Lumenocks. They looked pretty cool for seeing where your arrow is after the shot, seeing the flight path, where it hits the animal etc ... I was thinking on trying some for kicks for this year. There are a few different kinds but the only one I saw in person was these and they seemed to work real good.
http://www.burtcoyote.com/
http://www.archersflame.com/
http://www.tracerarrow.com/page/page/996884.htm