Where to make overlays - please help

I'm learning DVD Studio Pro, and have come across a stumbling block. In my tutorial, it says to easily create simple overlays (underlines) in a picture editor. But I don't have anything other than FCP Studio Pro on my machine, and I don't feel like shelling out for Photoshop, when all I want to do is draw some underlines on text. Is there a way to create overlays in Motion, or can someone suggest a cheap picture editor that would do that?
Thanks!

Just solved the issue by buying a little tutorial online. Anyway, if anyone else wants to know how: you can actually create shapes in Motion, and a small rectangle will serve as an underline. Fill it with black, and then add a white layer underneath, export as a TIFF, and voila, you have your overlay. All without buying Photoshop. :-)