I've been letting my kids help dye their own and it has increased the interest dramatically.
We have a big one that is green; it is usually just grass when there's a picnic but it has been a cape or a tent as well.
We have a bunch of little ones that are all kinds of things. Some other posters covered some of those possibilities. If there's anything that surprises me about having little ones (mine are 5m, 3, and 5) it is the HUGE number of original ideas that they come up with, things I never would have brainstormed in a million years. (Doll underwear? Teddy-bear sling? Superhero web-target?)
I do have a boy and he does love the playsilks. He uses them differently from how my daughter does, but this may be his age rather than his male-ness (he is 2 years younger). My daughter tends to arrange intricate scenes (making picnics, building a booth and pretending she is a vendor at the farmers' market, travelling saleswoman, etc) but he tends to do things that require less arranging, using them as hats, scarves, capes, simple tents, things like that, although he will play along with the more intricate games my DD devises.