i don't remember where i got this one (sorry!), but here are a few patterns you could try:
mine are backed with a double layer of terry cloth for extra absorbancy (i heard a rumor that babies drool and spit up a lot) and have snap closures. the husband kindly helped out with attaching the snap closures, since i tend to hammer my fingers when i do it. the patterned fabrics are designed by me, and you can still win some fat quarters to make some of your own. a fat quarter can probably yield two or more.