Tivo hacks Generally aren't to hard... but in order to get your data off of it, you need to open it up and connected the HD to your computer to get the file off of it, also the tivo filesystem (NTFS I believe) runs linux so that could provide some trouble, and when you do get the file, it's a very large HQ Mpeg-2 File, so before putting it on a filesharing service it would need to be converted to Divx, or a lower quality MPEG.
As this would be your first attempt, I would reccomend against it, as it can be somewhat tricky, and you will of course void your warranty when you open it up.
Tivo Captures when properly converted provide some of the best video quality thoh, imo.