Can you play avi movies on ipod?

You cannot play .avi files directly on the iPod. If they play in iTunes, simply right click on the file and choose "Convert to iPod format" to create an iPod-compatible copy. If you can't play them in iTunes, then you will need to use a 3rd party converter to get them in the proper format, which is .mp4
I use Quicktime Pro and/or Nero to do that when I need to.

Anytime. And .mp4 is the best format to convert to, the iPod understands it just fine.

Wait a sec... I just realized that this post is in the "iPod with Color Display" section. If you have an iPod with Color Display, you cannot play videos on the iPod.

you can, but you have to convert them first. I play movies on mine, and it's great! Just buy a program to convert your movies. try searching "ipod movie converter." but, make sure you buy a program formatted for you computer, and make sure what you're buying or downloading is reliable. I haven't found a free reliable pc ipod movie converter, but that's not a problem because I have a mac.

Hi, can I just check what you mean by "ipod with colour display"? I would mean a 4th generation photo ipod. Rather than a video ipod which also has a colour display?

Thanks!

And also, as you have a mac, what is the name of the ipod movie converter that you use? Cheers!

QT pro is not the best choice.
it support few video formats and has a fatal bug when you convert muxed video to mp4. muxed video which means the audio and video are on the same track, quicktime or iTune can not deal with this kind of videos,
you can spend your $29 to buy a professional iPod video converter like handbrake and/or Wondershare video to iPod converter

Windows XP

you can try handbrake, it is free,and it runs on pc and mac both.

Yeah, the actual name of a 4th gen iPod is "iPod with Color Display". A 5th gen is "iPod with Video".