I recently purchased a Tritium FOB from DealExtreme-pictured below beside other items for size comparison:

http://img189.imageshack.us/img189/956/edcmay09004.jpg

The 30 second review:

1. Cheap, all things considered-small, compact, seems to be durable, and serves its purpose-finding my keys in a near pitch dark environment. It arrived in about 2 weeks.

2. You could never use this single, point of light to read by, attract attention, or guide your way through a dark house/cave -but again, as above, absolutely serves it’s purpose for what I wanted. ;D

For those who are interested, go to deal extreme and search for tritium FOBs.