Good way to build a grid in Photoshop, Illustrator or InDesign?

[M A V I C]

Thanks guys, I think I've got it. A couple things to clear up:

- I realize I wasn't incredibly specific in my first post (eg number of images I'm using.) This is mainly because I wanted feedback on different ways to accomplish this for my future reference as well. It seems like I want to design more things that would use similar techniques so I was trying to find the best ways to do it.

- As I noted above, I could have probably figured out how to do this on my own but I wanted more ideas on how to do it. So some of you gave ideas on how to do it with multiple images, or single... or different ways altogether... that's what I wanted to hear. In a mockup I did I only used four and now the client prefers that over the 16 they were going for.

Thanks again.