I've heard that sleeping with your hair in a hair sock is a good idea for those with long hair, and I'd like to try it, but I have questions.  Can you buy one, and if so, where? Or do you have to make one?  Do hair socks work better than using satin pillow cases?  My hair is just getting so long now that it gets a little messy overnight when I move around.  I could braid it, but my hair is pretty fine, so it doesn't hold a wave well. It might look funny in the morning.
Anyways, I would appreciate any and all advice.  Thanks!

I'm pretty sure you can use any sock that's long enough to wrap your hair around and still have room on the ends to tie the sock together.
Bikerbraid is the one to go to on this one-I think she sleeps with her hair wrapped up in a sock frequently.

Hair socks - yes, that is my specialty!  ;D

I used a a soft, cotton crew sock (that I lost the mate to many, years ago), to roll my hair around.  I have also braided my hair, coiled it and dropped it into the sock, then secured the sock with a bunjii or scrunchie.  I've even used the leg of pantyhose to put my hair in when biking in really windy conditions.

No special socks are needed, just whatever you have available.

Thanks Sakina and Bikerbraid!  I'll have to try a hair sock tonight.  Bikerbraid it sounds like you are the expert!