The New Oxford American Dictionary has this quaint tradition of naming its "Word of the Year" from its list of new entries for the upcoming edition.

Nevermind your 300 million members, Facebook. You have arrived after inspiring this year's winner: unfriend.

That is, as in to "unfriend" someone from your Facebook list of friends.

It's actually more like a shunning. Facebook has it set up, of course, so you can drop a friend from your list quietly without notification to the new persona non grata. The hope is that they won't notice the sudden absence of your wall postings, etc. from their live feed.

Facebook has become enormously popular and for those 300 million folks, enormously mainstreamed into daily life, very quickly.

It remains to be seen how social networking and social life will ultimately sync up.

Lingering mysteries include:

1. Longterm effects of mixing business and personal contacts.

2. Figuring out how many "friends" are too much or too little. I think there's a been a rush to "friend" without thinking just to build up lists. I anticipate "friend" layoffs at some point, when enough sticky professional and personal situations arise.

3. Is the new transparency, interpersonal transparency? Keeping our private lives, private, is getting increasingly difficult. At what point do we all just say "screw it"? Employers will just have to understand that their employees sometimes get drunk in the Bahamas with their old college buddies, some have alternative lifestyles, some make inappropriate jokes (but they know not to do it at the office) and some occasionally complain about you among their friends. With 300 million blurring the lines and going strong on Facebook, it seems inevitable that weeding out people for any of the above will eventually leave you with a very small talent pool.

Last year's word of the year, by the way, was "hypermiling". Hypermiling is action taken to improve gas mileage; like inflating your tires or empyting your trunk to lighten up the vehicle.