I notice alot of sites that let you download youtube videos for ipod always have to convert them first.
Heres a really simple way
just take the video id and place it into the following url
non-working example
http://66.112.210.78/mp4/VIDEO-ID-HERE.mp4
working example
http://66.112.210.78/mp4/NT-2fenmLnc.mp4
video the above example is from
i wont keep it up forever but for awhile anyways