Is there a light weight strobe light available for model gliders?

If I can interpret the core of your request - you want a visible plane at height in sunlight?
There are LED strobes you can make/buy (google) but I doubt they are much use in daylight within modest battery requirements.
However try this: Chrome Monocote wing LE strips -
http://www.rcgroups.com/forums/showp...3&postcount=10

Im not sure if you want to spend the money on a real xenon strobe kit or not but I thought I would help with a company that supplies simple soldering kits for blinking lights. I bought the double high brightness LED kit for wingtip lights.

http://electronic-light.com/begin.html

Thank you for the information! I'm new to R/C gliders and having a great time. I built free flight gliders a great many years ago as a teenager which was fun, but this is far better.

I'll give the reflective tape a try first to increase visibility. Got into thermal the other day and it carried my bird up to where it was a bit too high and far out to see well to keep good orientation. Did a tight spiral to loose altitude and bring the bird back into easier view. Just a three channel EP bird for now. Flying with the buzzards could get ya in trouble if you track with them too far.