Looks good. Design point: I'd try to stick with a grid. The "beta" text seems to have a random position off to the right, and while the table of example searches are functional, they could use some consistent cell padding.

On the search page itself it'd be great if you tried to align the left margin better. Right now the top bar hangs out, which makes the page flow poorly for the eye.

In general, reduce number of vertical columns of alignment. A grid helps that. That's my advice.

Read this blog post / attached PDF -- it's fantastic: http://www.subtraction.com/archives/2007/0318_oh_yeeaahh.php