I started a new Squidoo Lens called Coolest Knitting Patterns using just squares and rectangles. I am pretty proud of this little piece of work - its a listing of patterns you can make that require no shaping! Everything from the traditional poncho, to the ever so cool "squares slippers" I am making for the kids are listed. I've even tried to focus on a lot of things in garter stitch so this is a great listing for beginners who want to go beyond scarves, but want to avoid doing decreasing, increasing, and all that sort of complicated finishing that lazy knitters (like myself) just don't like to do.
Of course these patterns are perfect for loom knitters, even though it is perfectly possible to do shaping on the looms, sometimes its just easier to stick with squares and rectangles!