Pet peeve: when web pages have auto-loading music, especially the kind that has a non-existent or hard-to-find "mute" button. Do people not realize that a lot of online readers have dozens of tabs open at one time to accomodate a high volume of data gathering?
This is a big part of the reason I hate looking at MySpace pages. The cacophony of melodies and rhythms that assaults my ears when I open more than one MySpace page is enough to make me want to track people down and put tape on their fingers.
A lot of people are listening to streaming radio, or iTunes while they read stuff online. To put auto-loading music on your page seems to assume that readers are looking at your page and your page alone, which is sort of ridiculous. Please, people, share your favorite music if you want to, but make it optional...put a play/stop button in the upper left or right hand column on your page.