I ordered a Glo-Toob and this tiny miniature ethernet loopback jack from ThinkGeek. I ordered them like two weeks ago but due to some shipping issues they did not arrive until today.
The Glo-Toob is very nice though quite a bit smaller than i expected, it takes one tiny A23 battery which looks like a AAA battery cut in half, however it puts out 12 volts and supposedly lasts for >60 hours inside the Glo-Toob. The Glo-Toob is waterproof to 11,500 feet which is pretty significant considering that's over 2 miles. The battery is also very cheap compared to the CR123A for which i have paid >5$ per battery (though the site I linked to seems to sell them forsignificantly less). I use the CR123A batteries for my INOVA X5 LED Flashlight. This light is brighter than virtually any flashlight I have ever seen or used before; it certianly outpreforms any flashlight of it's size. The X5 is about 4.75" long and .860" round and solidly built. The X5 projects it's beam up to 120′ and is visible up to 2 miles away! INOVA seems to have released a new light the XO, it's about the same diamater and an inch longer uses a single LED and they claim it has an effective distance of >200ft and signal distance of >2 miles. Sadly both the X5 and XO are only "tested" to a 150′ depth though I suspect it could survive much deeper. I run off to search Froogle for the XO.
Thinking of google I need to thank Steve for getting me a Gmail account.