I'm interested to know if anyone knows of a good AVI converter. I need to convert AVI files to some other format compatable with Sony Vegas 5.0. I've found some, but they are all crappy. And those that are good have some stupid print on it like, "To remove this nag, give us a whole ton of money!" Any program that will retain the original quality would be great...

Any suggestions?

try VirtualDub (http://sourceforge.net/projects/virtualdub/). The interface is a bit weird, for me at least, but its converted everything i've thrown at it so far.

Zamar (http://www.zamzar.com/)- you don't have to download anything, its free, and will allow you to converter to the following video types:
3gp - 3GPP Multimedia File
aac - Advanced Audio Coding File
ac3 - AC3 Audio File
flac - Free Lossless Audio Codec
flv - Flash Video
gif - Graphic Interchange Format
iphone - MPEG-4 (H264) Video File
mov - Apple QuickTime Movie
mp3 - Compressed audio file
mp4 - MPEG-4 Video File
mpg - Moving Picture Experts Group File
ogg - Ogg Vorbis Compressed Audio File
wav - Windows audio file

Wouldnt that be a lot slower than downloading a 10 mb or so program and running it natively? I mean, how does Zamar work? ( I haven't been able to even load the site). Does it upload the file to their own servers? or does it run on your machine? If it runs on your machine, it still downloads something, if it runs on their servers, that a long upload time, and if the video file is over 100 megs, its an unbearably slow one at that.

First you upload it to their servers, then wait well they manage the file (time is variable), then they email you the download link...
So it is slower, but has the advantage that you don't need to install anything and you can download to any computer.
So, if the the videos are big, and/or numerous, then VitualDub is defiantly a better choice.

I always recommend SUPER (C) (http://www.erightsoft.com/SUPER.html), it converts between lots of file formats, with a great deal of customisation and flexibility. It's amazing how many times this question is asked...

EDIT: Here's a screenshot of it
http://forums.civfanatics.com/uploads/14073/superc.PNG

Thanks guys, I'll be trying these out tonight.