Sky Cast is designed as a multi-platform service to make people more involved in their favourite TV shows and share their own content, and touts the catchphrase 'Film it, Load it, SkyCast it!'. The service uses Google Video to power it and is currently in a Beta testing phase.
The FAQ for the service confirms that you do not need to be a Sky TV subscriber to make use of the service, you just need to register for Sky Cast. One attraction is that subscribers get the chance to rate other peoples content with the best material potentially appearing on Sky TV. There is a maximum length of video that can be uploaded which is ten minutes, so no three hour epics will be possible. At the suggested bit rates of 2Mbps and 5Mbps, 10 minutes of video equates to between 150MB (MegaBytes) and 375MB. For those watching content, the bit rate is important since those with a slow connection may see reduced quality video, or those with a fast connection may consume over 2GB (GigaBytes) an hour if watching lots of material.