Seperating foreground from background

[do_pete]

One of my teachers has a picture with some people in it but it has an ugly background. He asked me if I could remove the background and insert a better one. What piece of software would allow me to do this and how would I go about doing it?

[[Gandalf]]

Any decent photo editing software would allow this... Paint Shop Pro, Photoshop, Gimp, etc.

What I believe you would have to do is use a selection tool and select the whole background section. Delete it, create a new background layer, and paste your new background image (make sure the background layer is below the main image layer).