i am prepared to create a website with transparency supported images. i cant create these images myself but have to take them from many resources on Internet and then modify. I like png images (png24) but i soon realize that most users from all over the world still use IE browser, especially version 6. Unluckily, IE6 doesnt support png24 images but png8 and gif images. Do you know how to convert (or do anything else) png24 to png8 or gif using Photoshop and maintain quality?. I tried many times but still not succeeded (converted images are in poor quality).

I had the same problem when I started with Joomla. There's a plug-in for Joomla that shows transparency on PNG images for Internet Explorer 6 users.

Anyway, I wouldn't worry about that, use PNG images whether or not IE6 users can or can not see the transparency, cause I don't know how would you do the thing you asked..

There are actually about four ways to fix that png bug.

I would suggest the official MS png fix that uses their iepngfix.htc file, but here are some other options for you to explore:

http://snipplr.com/search.php?q=png