Michael,

"I've use Paint, which is part of Windows. I've also used GIMP which runs under Linux or Windows. Irfanview may do it as well. Just about any graphics manipulation program will let you do it."

Must admit I have never used any version of Paint.

Did a quick search and found
http://windows.microsoft.com/is-IS/windows7/Using-Paint
http://fay.iniminimo.com/paint7.html

Also found other alternatives
http://fay.iniminimo.com/free_graphics.html

Do you have any examples of marking up PCBs using Paint?

Should add that I am trying to reduce the number of apps to try to those others have found useful to markup PCB photos.

Ken