YouTube has announced that it is to let visitors to the video sharing site download video content to view without the need for an internet connection, in what is probably the biggest shake-up of the service since its creation.

Following the company's announcements that it would allow Gmail and Google Calendar services to be accessed offline, YouTube is the latest site from the Google stable to ditch the need for web access.

"Many video creators on YouTube want their work to be seen far and wide. They don't mind sharing their work, provided that they get the proper credit", said product manager Thai Tran on Google's official YouTube blog. "Using Creative Commons licenses, we're giving our partners and community more choices to make that happen. Creative Commons licenses permit people to reuse downloaded content under certain conditions".

Hoping to appeal to publishers large and small, Google has also announced that it is testing the ability to let video publishers charge viewers to download videos.

"We're also testing an option that gives video owners the ability to permit downloading of their videos from YouTube. Partners could choose to offer their video downloads for free or for a small fee paid through Google Checkout", Tran said in the blog post. "Partners can set prices and decide which license they want to attach to the downloaded video files".

Google has already started tests with a number of publishers, specifically universities, to allow them to share lectures and research. Free downloads will be available from Stanford, Duke, UC Berkeley, UCLA, and UCTV.

A small number of other YouTube partners, including khanacademy, householdhacker and pogobat, are also participating in this test as an additional distribution and revenue-generating tool.