My sister tells me her DD (7) is sleeping a her friends house this Friday....I think that's very young!
I mean..not if they know the family really well...old friends kind of thing...but they don't...they've had a playdate or two and my siter has never even met the childs Dad!
she's met the Mother once when she came to collect her DD from my sisters house where she had spent the afernoon playing...and once when she went to the womans house to collect my niece...am I really out of touch or over protective?
I just can't imagine packing my 6 year old off in a year to sleep at a strangers home!
I thought 11 or 12 was more the age for this kind of stuff...well maybe 10... 
[clingy parent emoticon]