LinkedIn.jpgLinkedIn, the social networking site for business professionals, has introduced a feature to let people find “recommended” service providers.

This move takes LinkedIn, the Sequoia Capital-backed Palo Alto start-up, beyond its insular focus on the business networking set, and brings it closer to a Yellow Pages model — making it much more interesting.

If you are searching for an attorney, for example, no point going to the phone book. You can click on the “services” tab at LinkedIn, then select “attorney” and see if anyone in your network as recommended an attorney in the field you’re looking for (see the graphic below for the example of what we see when we select attorney; we see several recommended attorneys one degree away from us).

If we select one of the attorneys, LinkedIn takes us to the recommended attorney’s profile on LinkedIn, if he has one; if he doesn’t, it takes us to a basic description as provided by the contact who recommended him.

LinkedIn lets you search for all recommended attorneys on LinkedIn — even those outside of your immediate first-degree network. If the service provider is outside of your first-degree network, you use the same process as usual to contact them: send a request through your network. If they have a profile, you can pay to send them email directly.

The useful service could help LinkedIn reach the “tipping point” it is looking for. The Palo Alto company has been quietly working away, signing up about 420,000 people in the Bay Area alone (of two million estimated total professionals in the area, that is getting impressive). For most of us, LinkedIn hasn’t been a “must have” service. But slowly, we’ve noticed it improving its relevance. Once it gets close to a million professionals in the Bay Area, we may begin to start seeing it as a decent directory of people in our area. Each one of these people has a profile on LinkedIn, so it is useful for doing research on people.

Co-founder Konstantin Guericke told us gardeners, house cleaners or tree trimmers are unlikely to sign up on LinkedIn and have a profile. But once someone on LinkedIn has recommended them, the service provider gets an email, telling them about the recommendation, and giving them an option to sign on to LinkedIn to create a profile to better control what people see about them. Konstantin said some 20,000 service provider recommendations have already been made.