Do like I did and wear them on your one functional foot while in a fixator and/or cast following leg surgery.
On second thought, scratch that; it was no fun at all.
In the spirit of Dogzilla’s post, you can also use them to make draft dodgers. Don’t put so much rice in the sock (but still tie it up), and put it at the base of your door, window, unsightly mouse hole, etc, to block any drafts you may have in the winter.
If you ever have children to entertain (or who you want to entertain themselves), make them into sock puppets (the good kind, not the MB kind).
Make hair out of yarn (braiding it works best) and sew or gluw it on. Add either googly eyes with glue, or draw eyes with laundry/permanent marker. Use dye, markers or cloth to make clothes. Puppet city! You can even color in the mouths or make tongues with felt.
Kids love puppets.
Everyone loves puppets.
Ooh, let’s put a sock full of FOOD in front of the mouse hole. That sounds like a good idea 
Ooh! This reminds me of a great toy I had as a kid - a square plastic weaving loom (like the one pictured at the bottom of this page), which came with a bag of cotton loops (the loops were, as far as I could tell, little crosswise sock-slices). You string the loops on the loom, weave the horizontals through the verticals, and - lo - instant (silly-looking) potholder.
Yay for sock crafts!
Heh heh heh. Check that out.
I had one of those when I was a kid! But the loops in mine were some synthetic stuff that melted when actually used as potholders so my mother, grandmother and aunt just hung the ones I made for them on the wall as dusty decorations.
Stupid loops.
What about sock monkeys? Sure, you usually use those funky brown socks with the red toes, but your monkey could be an albino!
I know someone who puts a sock over their cat’s head when it’s time to clip their claws. This makes the job easier supposedly, but I haven’t tried it myself.
And no matter what you do, don’t drop an open rice sock on the carpet. Your vacuum cleaner will not thank you.
In case anyone is wondering where all those socks go, here is the currently accepted theory among quantum physicists.
Please, whatever you do, keep your stray socks away from wire coat hangers! In our house, they conspire with one another and multiply quickly!
Sock doggies are nice but what about, oh I don’t know, some other kind of animal perhaps… (hint hint)