My daughters got me a red Life+Gear Glowstick for Christmas. It is bright and useful for signaling. Pretty handy item. It found a place in my response bag for work.
Haven't had any personal experience with this product but may have to pick one up to test out but another glowstick alternative that I have had a lot of success with is the Night Ize LED Wand.
Before I went on my last deployment, I bought a couple similar wands in the Base PX. These were modular, with the LED light in various colors and a wand which could accommodate a light at each end. I had a green LED on one end and a white LED on the other end. I think I have it in one of my BOBs somewhere...