The March issue of GQ sports an excellent article entitled Do You Have an Office Wife?
She knows you better than anyone. She'll listen to your problems. Laugh knowingly at your jokes, and most important, mock coworkers with you. You couldn't survive without her. Just don't tell that to your real wife.
Gender specificity aside, I think this idea is fascinating. Do you have an office wife? Office husband? Are there office boyfriends and girlfriends, office friends -- colleagues we need at work like we need our family and friends outside the office? I'm not talking about romantic overtures, or coworkers you may actually socialize with extra-curricularly, but comfortable relationships that parallel those in our non-work lives without crossing the home-work gap. Who do you eat lunch with all the time? Who are you especially pleased to see in meetings? Who do you make a beeline by every day, if not every other?
Of course, there are risks involved in such workplace connections. Think the 1957 film Desk Set -- a great movie that touches on change programs, technological progress, mergers, and layoffs... as well as a character who treats his office wife like one for too long.