I have given away a couple of Klein bottles to collaborators I have really enjoyed working with, as a token of appreciation. He sends emails that show him packaging, and a bunch of eccentric paperwork accompanies the bottle, which are a delight. Visiting him at his lab is on my todo list (his website mentions "You're welcome to stop by for coffee & chat - please call ahead if you plan to visit."), I don't stay very far from his place! Maybe I will get a copy of his book signed too.