yea, photoshop or something along the same lines.... if you get the person doing the design to give u copy and show you how to do it, its easy enough.

if you have the foto and the logo both open in seperate photoshop windows.... u can drag the logo from its window onto the other containing the foto. the logo will drop on top, and u can place it where u want. assuming that everything is right, you just 'save for web' and 2 become 1.