Current sig: "The best thing about this sig is that once you realise it doesn't say anything funny, it will be too late."
A paraphrase of something like that was on a shirt. I thought it was funny, but didn't have time to stop and buy the shirt (Christmas shopping and all).
New sig: "Due to budget cuts, the light at the end of the tunnel will be turned off on weekends."
I recall reading or hearing that somewhere, though I forget where.