I was looking for tools to watermark the photos that I have taken. Downloaded and tested a few of the free tools.
Finally I settled with the following two:
1) Unidream's Powerbatch http://www.unidreamtech.com/
2) Faststone Photo Resizer http://faststone.org/FSResizerDetail.htm
Both I found to be quite easy to use, and flexible to adding watermarks. And they are free for home users.