For those of you unfamiliar with LinkedIn (all both of you), it's the ever popular and growing professional social networking site: underline the word networking. That's what LinkedIn is all about: professional networking, sharing contacts and colleagues, fishing for work, recruiting, looking for expertise on a business or career issue, etc.

LinkedIn is having a busy week. First, check out it's new look. The homepage got a facelift this week.

Second, they made a pretty big announcement revealing actually some of the meat and potato details on the open source platform that is to debut allowing developers to build applications on top of the LinkedIn platform.

It's called the "Open Social Platform" and will allow people to put LinkedIn widgets mashed up with their own applications on their own sites, as well as on their LinkedIn profile pages. (So for example, imagine mashing up your LinkedIn contacts with Google maps and giving yourself a widget with a visual display of where your rolodex is spread out allover the country or world).

There's also now a new newsfeed option on the site.

And a busy week wouldn't be truly busy without some fun rumors to get us all in a twirl. The drumbeat of a possible acquistion is getting louder and louder. The most likely party to snap up LinkedIn: The Wall Street Journal.

LinkedIn would be a tasty treat for Rupert Murdoch. LinkedIn has 17 million registered users (albeit a significant chunk or inactive). They get 42,000 new users signing up every day.

More juicy and tasty: the median income of the LinkedIn user is higher than the average WSJ subscriber (slighty above 100k a year versus slightly below). The average age is 41 for LinkedIn versus 48 for the WSJ. (as quoted by LinkedIn to Read/Write Web)

And while Rupert thinks about doing a little holiday shopping for a social networking site to go with his new business newspaper and cable television business news channel...

Business owners might want to think about those demographics in terms of drumming up deals and new business without ever leaving the office.