Baby Felix Klein’s family probably didn’t give him lots of useless presents around the holidays, and he turned out okay (aka brilliant mathematician/physicist). All of  the Holiday Sales are already starting, trying to entice all of us poor people to dish out dollars for useless junk. So I thought I’d start a list of mathy gifts under $15 that are sure to please. Everyone knows that mathematicians love to be disoriented — or at least they know that being disoriented is nothing to be ashamed of! I suppose these might also make good extra credit projects to give your students as well (maybe not the first one). • Make a Glass Klein Bottle for your favorite mathematician: What’s a Klein Bottle? Take a cylinder and glue the ends together with opposite orientation. Can’t do it? That’s because it can’t be done in three dimensions without letting the cylinder intersect with itself. Acme Klein Bottles is a company that specializes in beautiful glass Klein Bottles that are, in general, pretty expensive. BUT, the good news is Acme Klein Bottles, there is a$10 option that may appeal to those conservationists/penny-pinchers among us. This “Jigsaw Puzzle” comes with a free band-aid!