How to Make a Handmade Crochet Cat Bed. Very Cheap and Easy to Make!--This would be perfect for our cat, Ninja. he has a bed from when he was a kitten and he still loves it, but it is getting a bit small for him.
splityarn calls this the "Easiest Knitted Sweater Zipper Install Ever" and it looks like it might be. I haven't tried it yet but I'll let you know if I do - my one attempt to put a zipper into a knitted sweater came out OK, but not this nice.