The biggest problem that good developers have when it comes to recruiting is that they hate recruiters, and the best way to guarantee that you get spammed by every recruiter in a thousand-mile radius is to tell something like LinkedIn that you're looking. Mighty Spring solves this problem by providing candidates with the ability to check out relevant jobs and indicate interest _completely anonymously_. No alerting recruiters. No alerting your boss.

Disclaimer: I'm the front-end guy for Mighty Spring :)