The New York Times’ Randall Stross has a story this morning about ‘Sifting the Professional From the Personal‘ when it comes to social networks.

Attorneys and other professionals have gravitated towards LinkedIn because it is ‘professional.’

Among online networking sites, LinkedIn stands out as the specialized one — it’s for professional connections only. That distinction has given it staying power as Facebook’s predecessors have dropped away and as Facebook has grown to dwarf other sites. By keeping professional identity pristinely separate from the personal and the messy, LinkedIn, which is now publicly traded, has grown to more than 135 million members in 200 countries.

At the same time, Facebook users visit Facebook more than 30 times a month. Whether on a desktop or mobile devices, Facebook has arguably become part of the fabric of an awful lot of people’s everyday lives.

Stross’ article was on upstart companies pulling information from Facebook about a user’s education, current employer and job title, leaving out everything else. The idea is to present a professional social network without requiring professionals to complete a profile on LinkedIn, in addition to Facebook.

No matter what you think of the idea, Stross’ story raises the question in my mind of whether you want to keep your personal and professional lives separate when it comes to the net. Is it in your best business development interests?

Last week I shared on Twitter a blog post of mine on how law firms were missing the boat on how to use Twitter for building relationships. The Director of Marketing and Business Development at a large Northeast law firm replied on Twitter that she totally agreed.

The person happened to be with a LexBlog Client law firm and someone I was looking to get to know better. I asked via Twitter if she was going to be at that the Legal Marketing Association (LMA) Annual Conference in Dallas as I’d welcome getting together. She said she’d be there and definitely wanted to meet.

I followed up requesting to connect with her on LinkedIn. She obliged, but let me know she doesn’t use LinkedIn much. She uses Facebook for social networking and does not separate her personal from professional life online.

I went over and connected with her on Facebook. Low and behold she had a who’s who of business professionals, law and otherwise, among her friends at Facebook. She was engaging folks on Facebook in a real and meaningful way.

This morning she reached out and asked me to connect on Foursquare, a location-based social networking website for mobile devices. I obliged.

Her networking on Facebook, to me, seemed to be running laps around what she could be doing on LinkedIn. If she divided her personal from professional life by keeping Facebook to the personal side, she’d have lost an opportunity to grow her network, build relationships, enhance her reputation, and serve (and ultimately bring in) quality clients.

On the flip side, if I said, “Nope, I keep my business networking to LinkedIn and my personal relationships on Facebook,” I’d have lost a golden opportunity to build a relationship with a client.

Sure you CAN separate your business from personal lives online, just as you may do so offline. The question is whether you want to.