Seems Google isn't the only one with a neat little lab. The guys over at Yahoo! are playing with a rather cool tool they're calling Mindset...
At first glance the search results provided look like your average Yahoo! serps, but with an adjustment of a slidebar you can sort the results to your 'mindset' - in this case, your mindset can be either shopping or researching.
I played around with this a bit, and quite frankly I think the algo they're using needs a fair amount of tweaking. Maybe a few additional mindsets and the ability to tweak each a bit would provide more accurate results. Overall, though, the idea isn't bad at all.