changing avi files to quicktime

I need to shrink some movie files between 1 and 1.5 gigs to post on the web. Would quicktime be the best format and how do I do it...thanks!

There's a few you could try handBrake http://handbrake.fr/
or iSquint http://www.macupdate.com/app/mac/19769/isquint
or if your feeling flush
http://www.video-converter-mac.org/
or
http://www.macupdate.com/app/mac/15466/mpeg-streamclip

FLV is the best format for web. You would convert your video to flv , then upload the flv to web such as Youtube. I am using Total Video Converter,

http://www.etinysoft.com/total-video-converter-hd.html

Yes, Quicktime is the best format, especially if you hope mobile devices will view it.
I strongly disagree that flv is a good option, no Apple new Macs, iPod, iPhone nor iPad can watch them and many Mac people are also uninstalling Flash.

Handbreak works well and there are presets for the best size. Another advantage with Quicktime is that you can have it deliver the right size for the devices.