SezWho Offers Portable Reputations : Web Worker has a thorough writeup on the SezWho service which allows commenter reputation and rating across the web. Installation is really simple with their WordPress Plugin (also for MT). Web Worker seemed cautious about professing the success or viability of this service. However Read/WriteWeb, who is already using SezWho, was a lot more upbeat about the prospects. WeblogToolsCollection on the other hand, has been bitten hard by third party services and their scalability issues and I am going to shy away from this one for now. Sadly, it is quite hard to determine the dependability of a remotely hosted service from just their SLA and their promises, especially if their financial model is shaky.