Blue Sky Alpacas has a very nice cotton & organic cotton. I have some in the que for a baby blanket & booties, it feels wonderful but I haven't really knit with it yet. If you really want it bulky, you could use two strands: it's normally 4-5 stitches per inch on 7-9.
OTN: French Market Bag, Knitty
Craftster Circular Shrug
Saturday Market Bags (2 at once!), Magknits