Q&A: How old is old enough for sleepover parties?

Cheesehead Mom writes:

"At what age or developmental stage is it reasonable to start tryingsleep overs?  My almost 4 year old girl is begging for one, but I think she is too young.  Also, wondering if anyone has any tips on how to make them go well?"

(I clarified with Cheesehead Mom that she meant sleepover parties with other kids, not sleepovers with grandparents or other close adults.)

I think 4 is way too young, too. Here in NYC it seems like the rash of sleepover birthday parties has begun for the second-semester first graders. But this may be a regional/cultural thing. I just really can't imagine my almost 4-year-old doing a sleepover with only other kids his own age. He still sometimes comes in with me at night because he gets scared or lonely, so it just seems unlikely that he wouldn't get too scared during a sleepover.

What's the standard where you guys live? And does anyone have any tips to make them go well, either from the perspective of the kids attending, or the family hosting? I barely survived my 7-year-old's Wii Sports birthday party that lasted three hours (the yelling and grandstanding!), so I have no idea how I'd manage a sleepover...

And, while we're talking about it, how olld is the right age to go to sleepaway cap? One of my friends whose son is also in first grade told me that one of the kids in his class is going away to sleepaway camp for six weeks this summer, at the age of 7. I was flabbergasted. I didn't go to sleepaway camp until I was 10, and then it was for two weeks, and I was with two of my cousins. Do kids just go to sleepaway camp earlier these days? When would you feel comfortable sending your kid to one, and for how long?