Just to throw this out here... I doubt you need a custom module for just manage a grid of sponsor logos (if you want to avoid it).
You should be able to do this pretty easily actually just using a simple UL tag - a bulletted list - in an HTML module. By using a bulletted list, the maintenance is pretty easy, and you have a lot of flexibility down the road.
The only real challenge involves playing around with some CSS. But, the basics to it are pretty straightforward. First, you add your bulletted list and just put a class on there like "logos"... then, put this in your page's "header tags" setting:
(in a style tag)
.logos { width: 600px; list-style: none; line-height: normal; margin-left:auto; margin-right:auto; }
.logos li { float: left; width: 198px; border: 1px gray solid; }
.logos li img {max-width:198px;}
There's a nice example here: http://stackoverflow.com/questions/18...... I just tweaked it a bit
That will mostly take care of it, I think, and keep it very easy to manage.
Hope this helps,
Mike