Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Taken from the .Mac FAQ:

To connect to someone's Public folder using a web browser:
Open a web browser.
IMPORTANT: To connect to someone's Public folder on the web, you must use a supported web browser. If you're using Mac OS X, use Safari 2.0.2 or later or Firefox 1.0.4 or later. If you're using Microsoft Windows, use Firefox 1.0.4 or later or Internet Explorer 6.0 or later.

Enter the following address to connect to the Public folder: idisk.mac.com/membername-Public (where "membername" is the other person's .Mac member name). Be sure to use an uppercase "P" when typing Public.
If a password is required, enter "public" (without quotation marks) in the User Name field, and then enter the Public folder password in the Password field.

:)
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.