A really cool way to take up less space in your luggage is to stuff your tube of toothpaste into an athletic sock.

My mom taught me this over the weekend, and it works really well. First, you shouldn't have a tube of toothpaste that big anyway, but if you do, you can buy a pack of two athletic socks and then stuff the tube of toothpaste inside one of them, and you'll end up with a circular shape that you can put in your luggage or backpack as "a sock".