This isn't Facebook! And in response to argatoga's point I only neg rep the n00bs who start acting all bolshie when someone quietly points something out such as "please use the search facility" or "your thread actually belongs in X section". Mostly I leave them alone otherwise unless they bring something good in which case they get green blobs.
What I like about the rep system is that having come here to relax and unwind every now and then someone will post something that gives me a good, old fashioned belly laugh but which doesn't merit a post in response. It's nice to have a way to show appreciation privately without cluttering up the threads with a response.