I like to listen to podcasts while I commute. Often I run across a great video from a tech talk or Youtube that I'd like to download and listen to/watch in the car. Is there a tool I can use to fetch videos or cache them for watching on an iPod? Just the audio would be fine too as most of these are technical talks on Youtube, Vimeo or a conference site.
I don't want to pirate these videos or share them with anyone else; I'm often just busy when I come across them and I'd like to watch them later, when I don't have access to the Internet.