When I'm searching for information, especially client, business, or development-related research, I'm on a mission--I want to get in and out of a site as quick as possible (usually non-billable time) so I can quickly gather and compile my research. Whatever slows me down on a site is taking money out of my pocket.

I'm curious what kinds of code you have seen that slows you down on a site or has no direct contribution to the site mission, and what coding "gems" annoy you the most!