Roll-over effect request

[gumbystation]

I have a special request.

I'm looking to have a <div>. In it:
-- a single picture at the top, centered
-- below text

What I would like to have a a roll-over effect where you hover over text, and that centered picture changes. I want to display a lot of logo designs that I have. Maybe, instead of that, have miniture pictures (thumbnails) instead of text and the same thing happen.

I'm not sure what kind of code I should use. And from there, I'm not sure how I should go about it. Anyone have ideas for this? Or better, code that I could look at to try out?