Tami,
I actually have the male pajama pants with sock monkeys on them. They're fa-bu-lous.
That sock monkey photo is a "vintage style" one, however there's a number of places make them in modern styles and I've seen all kinds of sock animals and/or monsters too, but monkeys are the originators. My mother has a pic of her mother holding a sock monkey she made for my uncle many moons ago. MOre or less, sock monkeys were a cheap hand-made toy that was made of these specific red-toe socks (usually worn by laborers/outdoor workers). My mother made mine this year, it's sort of in the traditional sense of being simple and cheap looking whereas I've seen some elaborate ones. I like the simplicity of mine with just button eyes and not much to it.
I had one as a child that was a hand-me-down from my brother but I don't know what happened to it. I Know you can get really old ones, but they're not a brand so much as just a random thing you can make yourself if you find the socks and a pattern.
They even make mini ones made from real mini-socks that are just like 1/6 scale socks. I have a mini one hanging in my car actually, and it's hysterical to look at really. I've seen the mini socks you can buy online.
I gotta get another pair of socks though because my mother said she'd make the sweater and stocking cap for my sock monkey that you could do if you had 2 pairs of socks. That's the deluxe model I guess.
BTW Bill, you need not give "favors" to them to enjoy monkeys. THat's only if you REALLY enjoy monkeys, and really that's just wrong.... but it covers why Paris Hilton has one.