Mobile Hangers

A few posts back I said I was going to experiment with baby mobiles. These are the first objects I've crocheted, I'm pretty pleased with them. I think a space themed mobile would be really nice over a little boy's crib (not that I'm stereotyping!).

Now I just need to fathom a method of hanging them.  Any ideas?

I now need some more stuffing before I can start on my other ideas. 

Also, I'm not sure it you've heard of One Pretty Thing it has daily ideas of things to make using all sorts of crafts. It's the kind of site that makes me want to stay at home and craft forever!