Hi Kath, my ds had a sleepover for 9 of his mates on his 9th b'day a few weeks ago. It went really well.
Their main activity was t-shirt printing but we did other things too. On arrival they went straight into tea. They made their own pizzas, ice-cream sundaes and fruity cocktails. With a bit of preparation it wasn't as mad as it sounds!
After tea we split them into 2 teams. One went with dh who was in charge of the ds-es (as in nintendo), wii, pool, table football etc. I had the other team and we did the t-shirt printing. They each chose a picture and downloaded it from the internet, to go on the front (I had already done their names in grafitti style for the back) which they printed off onto transfer paper. While waiting their turn to design they helped themselves to tattoo transfers (that was a big hit). I had got t-shirts, transfer paper and tattoos from ebay - it worked out about £2 per child iirc. After an hour or so we swapped groups. When everyone had done a bit of everything we settled them down to a dvd and popcorn. During which I was able to iron the transfers onto the t-shirts.
The bit about groups was purely for my sanity. They knew from the start that there was going to be extra prizes for the highest scoring group. So I awarded prizes for quickest getting dressed, cleaning teeth, helping clear up, not shouting, etc etc. This definately worked. I also had to split them up into 2 rooms for sleep so points were awarded for the team that settled first. I had aimed to get them down by midnight. In fact they were all in their sleeping bags / duvets by 12.30 and asleep by 1am. They slept till 7am.
In the morning we had breakfast then did head to head games for more points. Prize-giving (everyone got something) was at 9.45 and hometime was 10am. I was really pleasantly surprised how great the kids were. I wasn't expecting any big problems, but all of them were really well behaved. Dh and I played good cop / bad cop which probably helped and they all knew what they could/couldn't do, where was in/out of bounds etc right from the start.
Things I would do differently next time would be to let the parents know what/not to send. We had enough bedding for them all, so only expected them to bring pjs, toothbrush and clean pants. But we were totally inundated with sleeping bags, airbeds, duvets, pillows, big rucksacks etc. Also if I had the option I would have sent my toddler and baby for a sleepover elsewhere, it probably would have been easier, but sadly we don't have that option. The only real mistake was letting ds ask a few extra mates in case some couldn't make it (twas a couple of days after christmas) but they all came!! So we had a few more than I'd hoped for. But it went really well and I would do it again. Next time ds wants to make boys' urban jewellery. Sorry for rambling, but hth!