ufdbGuard is the fastest URL filter available for Squid. It does 30,000 URL verifications/sec on a 2.8 GHz CPU.
ufdbGuard is free and based on SquidGuard.
You can download it at the 
home of ufdbGuard
and SourceForge.
A URL filter needs a list of URLs of undesired web content. Such a list is referred to as a URLFilterDatabase.
4 pages link to ufdbGuard:
