I like the simplicity of the page, and the pagination it uses. I was wondering what module it was using...I'd like to do something similar for a client, but i would also like for them to be able to update it in the CMS too...and was thinking about using either the Blog or the Calendar module to do this and then just modify it...but if there is a simple module that I can use then I would rather do that too.

Anyone know?

I am guessing you are referring to this module page - http://silverstripe.org/modules/.

Really all that is, is a <% control Children %> (each module is a child page of the modules page). These children are paginated (see the documentation for it here - http://doc.silverstripe.org/doku.php?id=private:recipes:pagination).

The thumbnails are fields on the ModulePage pagetype (added fields is covered in tutorial 2).

The blog module provides the same sort of functionality but if you don't need the blogging features then try out the pagination tutorials and just making pages.