In a neat yarn shop in Monterey (name long lost, alas) I got two great things: the irl of Ravelry, the source for all things yarny and a view of a couple of baskets crocheted with two strands.  I went home and tried that and, while mine didn't stand up as well (loose stitches? lighter yarn? bad proportions?), I liked the look and tried a couple of hats that way.