It was just a year and a half ago when YouTube conducted a mobile experiment that involved transcoding about 1,000 videos for mobile devices.

It’s come a long way since then. Today, YouTube can deliver the vast majority of its catalog, the only restriction being when content owners choose not to put their content on mobile, which is a small percentage, said Francisco Varela, strategic partner development manager at YouTube.

The goal is for YouTube to be accessible anywhere, anytime on as many screens as possible, which sounds similar to Google’s strategy with Android. Google bought YouTube in 2006 for $1.65 billion.

Of course, Verizon Wireless is one of YouTube’s biggest and oldest wireless partners; YouTube was available via V CAST before it developed a mobile site. Since then, YouTube has struck partnerships with operators around the world.

In those early days, only 10 videos were featured, and users didn’t have access to any others. That’s why YouTube launched its mobile site. “YouTube is about what you want to watch, not what we put up there,” Varela said.

With devices like the iPhone and broader availability of 3G, the mobile video experience has become much richer, YouTube representatives point out. A couple years ago, no one would have anticipated someone watching a 2-hour movie on an iPhone.

“It’s about using the handset as your primary means of Internet access,” he said, and people are demanding the same services they get on their PC.

As far as advertising goes, YouTube has done some display ad trials in the United States and Japan and saw “very good results,” he said. But it’s not planning pre-roll or post-roll ads, although nothing is off the table at this point. “We’re looking at a number of options.”