Silicon Alley Insider has a report on how YouTube is beginning to experiment with long-form content, which in YouTube terms, means anything longer than 10 minutes. So far, only YouTube's content partners can play, as per a memo sent to them last week:

"You now will be able to upload and monetize videos in your account that are longer than 10 minutes. This feature is exclusively for partners. Independent Film makers that partner with us will now be able to upload their feature films on our site. Please note that for long form content, the maximum file size is 1GB."

The report said that while YouTube previously limited video lengths due to bandwidth and copyright concerns, Google (YouTube's owner) is clearly thinking about advertising here. "YouTube sells ads against videos uploaded by its content partners, but there are only so many ads you can sell against a short, under clip. Presumably YouTube wants to figure out if it can sell more of them against longer clips." No word yet on whether or not these will play on YouTube's various mobile initiatives with their mobile site, Apple, Helio, and so on.