Oh my, with only 3 hours to prepare, it might be difficult to get the curls without using a curling iron or hot rollers.  My initial thought would be to do small rag curls - can you roll your hair up damp in the morning and leave it all day?  If so, the rag curls work best for me.  (I use a little bit of aloe vera gel on the ends so they don't get frizzy and the hold lasts longer).

A similar look (lots of curls), but without the hanging ringlets, would be to make loops with your hair and secure them with bobby pins or small clips.  Start with one or two ponytails, high on the head.  Then take small sections and make a loop, secure, make another loop, secure, etc until all of the hair is secured.  Then take another section and repeat.

Theh party sounds like fun - you must let us know how it goes!

You know.. I didn't think about this... but I wonder...

WOuld my hair stayed curled all day if I did the rag curls the night before?

And... do you know of any comprehensive site (with pics, if possible) that show how to do them?

AS you can see, I really want these curls!  

(edited to add)  Yes, you know.. if I did the rag curls the night before, I would have pretty curly hair (I can use large sponge rollers to create a lot of curl overnight, but only to the bottom 5 inches or so) that I could "touch up" with a curling iron then before the evening...

I was going to try to pin most of my hair up at any rate, but I'd like to have lots of curls around the crown of my head, so what's really important are those ends and the large sausage curls down the back... hrm...

I think I may be onto something here... 

I know there was a site showing the rag curls, but for the life of me, I can't find it now.  I really must have hubby take pics of me doing it.   

I do think if you did the rag curls overnight, your hair MIGHT hold the curl all day.  It really depends on your hair and the humidity conditions, etc.  Khrome's idea of putting your hair up during the day and covering it with a pretty scarf sounds like a good one!.  You could pull all your hair into one or two pony tails, roll up sections and tie off, then cover the whole thing with a scarf!  Let the whole thing down just before the dance, and everyone will be amazed at the curl and length of your hair!