Kayak.com

Since we're talking about Air travel, check out Kayak.com (old news, I know)

For those of you who've never seen it - it's a cool airline travel website which lets you do the normal searching and then 'filter' by a variety of criteria (airport, times, price) and it will refresh automatically (ajax baby!) on the spot.

The best part? They don't try to sell you the ticket - they send you off to the airlines website, but all the heavy lifting of searching has been done for you.

The real best part? The "Best Fare Trend" chart.

Hurray!