Judy’s Book, InsiderPages, CitySearch and others run relatively open social networks. In their efforts to attract as many reviews as possible, they run the risk of accepting some phony reviews sent in by business owners, competitors, sarcastic college students and others that might be incented to cheat.

Now Judy’s Book, the recent recipient of $8 million in VC funding, has sought to mitigate the risk by adding an EBay-like “trust score” to its reviewers. The score appears below user IDs, and runs from zero to 10. It is calculated in a way that makes it difficult to get above the median of “5.” Higher scores are reserved for regular contributors that have positive feedback.

“These kinds of mechanisms will become increasingly important,” said Judy’s leader, Andy Sack, who was speaking at Kelsey’s ILM conference. Conceptually speaking, I like the idea. But then again, I’m an “A” student kind of person. I don’t like being a “2.” Maybe I should post a little more and game Judy’s system. Or maybe I’ll just start using Insider Pages a little more.