One of ours has three camps this summer, all of them morning only camps (like from 9 to 12) and two of them are 4 days long, one is 5 days long. We use it as a socialization (gasp! :)) helper and just so he can get out and experience different things and kids. We have one car, and my husband uses it for work, so we don't get out as much. This is a nice change, although it's alot of work to get used to new schedules!
My daughter is too young right now, but when she gets older, absolutely! We'll definitely send her to camps :) I think that 1) they provide great opportunities to do/learn things that she can't at home and 2) it's important for her to build a sense of independence and self-sufficiency away from us, her family.