YouTube celebrated its fifth birthday on Valentine's Day. The youtube.com domain name was first registered on 2/15/2005 and the site was bought by Google 20 months later for $1.65 billion.

After the jump check out the top five YouTube videos of all time, including a terrorist, a baby and a history lesson. Have you seen them all?

Raise your hand if you've heard of Blendtec. I bet you are familiar with Blendtec and I bet I know how you first heard of their blenders - from their viral video series called "Will it blend?" That series, showing iPods and other unusual items being reduced to powder by a powerful blender, serves a strong branding message: If it can annihilate an iPod, it will make quick work of your smoothie.

According to the U.S. Census Bureau,there are nearly six million businesses in the United States. Think about the enormity of that number.That's billions and billions of dollars in revenue generation every year. That's also six million businesses that all require the same basic nourishment to survive - marketing and sales.

Since the days of the gladiators, sports fans have had an irrational bond with their favorite athletes and teams. Feats of athleticism evoke eruptions of euphoria or a tidal wave of tears as a game's final play unfolds.These strong emotions create an indelible brand loyalty that remains long after the season ends.

2008 has shaped up to be a crazy year for online advertising - the writers' strike drove people online and the presidential election and the Olympics are causing advertisers to boost spending in a down market. The timing of these factors has altered media behavior - making the business of online media anything but typical for the year.

All of the predictions that 2007 would be the year of online video came true in spades - it rapidly gained in popularity as a medium last year and its momentum continues today.

The long-lasting Hollywood writers' strike possibly hastened the migration of people to pass their time visiting online video sites due to the lack of television programming. It's not just old episodes of "Grey's Anatomy" they are watching online, but all sorts of content.

I recently had to stop Twittering. It was awful. The doctors said I would go blind.

Seriously folks, even for as big of an Internet geek as I am, I was completely overwhelmed by the massive flood of 140-character messages from friends and colleagues that bombarded me 24 hours a day. So at the time of this writing, I'm off the Twitter-pipe, for now.

But just when I thought I was out, my friendly editor/publisher of this very magazine suggests that I do my next Innovations piece on another new, hot social tool, called Seesmic. So much for cutting down on my information load.

There's no doubt that popular websites such as video clip destination Metacafe continue to be strong players because visitors know that when they come back again and again, they can be treated to fresh content to inform them and tickle their funny bone. They can play the short clips over and over again and send the links to friends without having to pay for visiting the site. Every page of Metacafe has a small, unobtrusive ad that helps support the site financially.

Neil Michel bought .mobi top-level domains as soon as they were available without consulting his bosses. As eMedia Director of Prosper magazine in Sacramento, Calif., he saw it as his duty to claim ownership of the mobile domain names before anyone else could capitalize on the company's brand name. He managed to snag ProsperMag.mobi and ProsperMagazine.mobi but not Prosper.mobi.

Steve Rosenbaum made his name on MTV and doing documentaries. So it's natural that he's into Web video. Rosenbaum is the founder and CEO of Magnify.net, which powers user-generated video (UGV) channels for Web publishers, media companies and video bloggers. The Magnify. net platform searches and sorts virtually all video available on the Internet based on a site's interest (such as hobbies, politics, music) and engages users to discover, share and rate them for relevancy and entertainment value.