Watermarking your photos?

Just curious as to how many of you watermark your photos?

I've been doing a lot of photo sharing online lately, mainly on facebook, but on Flickr as well and i've been thinking about watermarking my photos. I don't want to seem like I think i'm a hot shot or anything, because i'm not, i'm still learning ... but I'd like to have a little bit of added protection on my photos .. mainly the ones of my children. Just wanted to see who all does this.

I watermark all the pictures I post, I finally created a logo I am happy with that I am using now. I have two photo files, one unsized & unwatermarked, and another with pictures I posted that are resized & watermarked (For posting).