[wiremine]

I don't think slowing the site down really helps convey the speed difference anyways, because they aren't seeing it apples-to-apples.

Instead, I think you want to load two version of the site in to iFrames (or something) and throttle one.

This would also be a good way to show a user how crappy their connection is compared to a _real_ high speed connection: The problem isn't just that they are creating a "fast" lane and a "slow" lane, but the fact that US-based "fast" lanes are actually fairly slow to begin with.

[3rd3]

The iframes idea is a really good one because it wouldn't require changes to the web server configuration. The throttle could simply be simulated with delayed loading using JavaScript.

[xdissent]

Or you could allow certain elements like ads to load instantly for comparison.