I have just created two stamps from photographs using Photoshop as a
tool. An example is posted in the files section (Gracestamp3.jpg).
The other stamp became the stamp for the Looking for Molly HH. You
will have to find it or a box it has visited to see how it turned
out (it's pretty cool!).
Those interested in how I did this can go to a webpage I just
created which has instructions and hints. I hope that others find
this technique useful.
http://home.agalis.net/bcostley/Letterbox/PSinst.htm