spam clearing house

As you may have noticed, my blogs showed some instabilities yesterday. The reasons for this were some problems of lighttpd in conjunction with php5-cgi. The root cause for this: Trackback spamming(plenty of it) resulting in load problems. Well, this issue starts to get really nasty.
I thought a little bit about this problem yesterday evening, and i have an idea for a Web 2.0 service: A centralized spam clearing house. The basic idea is to redirect all trackback calls to this service, as long their do not come from the clearing house (or trusted systems). The service scans the trackback for spam and submits the trackback on the behalf of the originating server to the trackback functionality of the original server. The same should be possible for the comment function of weblogs. It´s similar to the service Feedburner offers to offload the generation of RSS feeds. I would even pay some money for such a server, as don´t have to rent faster servers every half year. I even thought about shuting down this weblog in june after the first big black-out of this blog. Fighting spam on different servers as a service would make my life much easier. PS: Would be a nice job for a UltraSPARC T2 server ;)