although it's not billed as such, http://mplayerhq.hu
is really really good for capturing from the card. other programs exist to capture from it, but their encoding is quite poor, as opposed to mplayer which has a really complex and powerful encoding core. you'd need a command something like:
mencoder -tv on:driver=v4l:norm=ntsc:height=360:width=480:channel=67 -ovc lavc vcodec=mpeg4:vqmin=2 -oac mp3lame -vop pp=lb -o file.avi
that will encode the tv signal to divx5. it s a little unweidly, but very powerful, so i would recommend trying it. esp as mplayer is a superb media player too.