What are your best short witticisms, suitable for use on a t-shirt, bumper sticker, or similar location? Ideally something that might make someone reading it think, or get curious enough to ask about it. Simple in-group identification is fine too, though.

For context, therufs is spending today at the NC Maker Faire making t-shirts, and asked me for suggestions this morning. As I was still mostly asleep, I wasn't very helpful.