Would it be possible to achieve this effect without images, purely with CSS?
Notice how the top horizontal menu items have blue borders that fade to transparent at the top?
Yeah, just have a regular <li> and make that fading part of an image. Just apply the image to the <li>
If you're fading it to white, you'll hae to make sure the page background is also white otherwise it'll just look silly.
Yes, with CSS3 you can do that, but it's not supported in older browsers.
Oh, whoops. I didn't see the "purely CSS" part he mentioned... D: