With all the paid reviews getting too hot inside the blogosphere, ReviewBack kick in with a fresh new concept. You review another blog but instead of getting paid for doing that, you get your blog reviewed in return. How it works? Register yourself with ReviewBack, fill up the required information and your blog will appear in the marketplace. Search through the marketplace for blogs of your niche and contact them easily through reviewback for a mutual review. You can even sort the blogs according to name, age, pagerank, alexa ratings, tags or categories etc. ReviewBack Marketplace ReviewBack plays role as a “middleman“, collecting bloggers interested in looking for review exchange under one roof. As far as I know, they are probably the first that provide such service. It’s a good place to look around if you are looking forward in increasing your traffic, or probably increase your PageRank - only if you are lucky enough to find high PR bloggers willing to trade a review with you.
I haven't used it yet...but i heard that they are pretty ok. You can get your listing highlighted if you blog about them.