I don't sign my posts, since it just doesn't seem right, considering you have a signature for that stuff, and it seems silly anyway. I mean, I don't want to have over 9000 posts with "~Alternative" at the end, because like everyone has said, it seems redundant, and I'm not really one for repeating myself.
One thing I've never really become accustomed to is that when people do it for everything, and it just seems weird to write something like that for something. I mean, I'll just put something like that if I'm addressing to someone, or if I'm writing a very long post or a guide or something, but just a little thing at the end of every post seems quite dumb.