Does anyone have any experience with this site? What did you think?

http://www.sidestep.com/

It is a great tool! I bought seven tickets from ORD to St. Thomas and had no problems.

One of the financial magazines just rated it the best web resource for finding the lowest airfares.
I've used it at times in the past but don't currently have it installed.
Many others at this website report using it regularly.

Note that the fares are typically a few dollars less directly with the Airline than those quoted on Sidestep.

It's a great tool for seeing what's available, but be sure to check fares directly as well.

djkbooks has it right on. You can really see what's available out there in various flights (number of stops/nonstop, etc) and price points.

It only works with Explorer as your browser, not Netscape. As a rule I normally use Netscape and was surprised that it SideStep.com not function with that web browser.

ttt

I have it installed and as Missjanna recently pointed out, apparently some security programs consider sidestep.com to be "spyware" and today I even got an offer for a free program to remove it. One of these days I'll send an email to sidestep and ask them to explain their side of this "spyware" issue.

SideStep's website makes the blatant claim that it installs no spyware.
On the other hand, SideStep is in itself spyware, so technically maybe they're not lying. Depends on what your definition of "is" is.

SideStep does automatically pass the URL of any pages you have visited, the content of any query you have made, and a unique ID to its controlling servers.