@ehBeth,
I've been on several forums that have a like / dislike feature, and I never thought it was a good idea. It tends to engender a lot of bad feelings. I've seen forums descend into chaos over it. Seriously. Arguments, bickering, flame wars, human sacrifice, dogs and cats living together... mass hysteria!
It doesn't bother me at all if someone votes my posts down. To be honest, I probably wouldn't even notice, and if I do it isn't a big deal. It doesn't really affect me in any way. It has absolutely no impact on my life. The only impact it could possibly have is the impact I would allow it to have by becoming upset over it!
The problem I have is that I tend to like a lot of posts. In the photo association game, for instance, there are so many funny and clever posts! If I start clicking, it's hard to stop, and that's considered spammy behavior in some places. As much as I like to let people know I enjoy their posts, I figured it's best to just ignore the feature entirely. But what the heck, maybe I should just click everybody up.