i bought my god daughter an ipod for her tenth birthday recently, i did have reservations about how easy it would be to download music on to it, but after an hour of the 10 year old showing us me and her mum are experts! she was really pleased with the ipod and i have found to my shame that she like most 10 year olds are much better at computer stuff than me.
Or this sunds strange but buy a packet of card anad paper from the paper mill as she might like drawing, craft, painting, making books. lots of cool stuff
I got my 11 year old "friend" A throw for her bed and some cushions to give her room a grown up look - you can pick up some lovely throws from Tesco - got a lovely soft cream throw on my bed , for a brown cosy one from woolies too - cushions are pretty cheap from places like Wilkinsons
My DD got a few horse riding lessons for her 10th. Enough to get her to cantering on a weekly basis(about 6), then she could have anymore lessons occasionally. I didn't think 10 was a special birthday. As for ipod, any self respecting 10 year old has no problems downloading music.