Around about a year ago, I made a nalgene cozy. Only it wasn't a nalgene, it was a Target Eddie Bauer one. But you get the idea. It looks like this:
While at shmoocon, shmoo was traipsing around with it, (No, it didn't have Absolut Mandarin and Dole Pineapple Orange Juice in it. Really it didn't. It was... just plain orange juice. Yeah... that's the ticket.) and another of the shmoon liked it and requested one of me. But without the handle, the shells, and without the girly colors. Freshman is a cute fella and shmoo likes him, so I said ok. Furthermore, it just so happened that I had packed some 100% cotton with me from the stash so I could perhaps make a washcloth if I got bored with the sock knitting. And I was even fortunate enough to have a proper sized crochet hook in my little case of supplies. Freshman was a lucky man. I asked if the yarn was ok and got started. I should have been done with this yesterday, but we were hungover and trying to get sick, so alas, I now have to mail it to him as opposed to just throwing it at him in person.
I present, Freshman's Cozy in 100% Hand-Dyed cotton from Mystical Creations I think. I got it off of eBay. I used a size G hook and it's just double crochet with a single crochet band at the top to finish it off. No pattern or anything. It's just a tube of the appropriate size.