Price comparisons in real time

Trolling around BestBuy.com for a deal on a Canon PowerShot digital camera, I come across an SD450 for $349.99. Not bad for 5.0 megapixels and 12x zoom. Suddenly, emerging from my browser's toolbar, is word that more than a dozen cheaper alternatives - one of them for $65 less than Best Buy's - are lurking around cyberspace.

My ally: Dealio, a stealthy plug-in application for PCs (Explorer 5.5 is the required browser). The idea: Land on a consumer-electronics gadget (don't look for appliance items like toasters) at any of the 20 biggest e-commerce sites - Amazon, Overstock, or Target, to name a few - and Dealio will tell you if the price is right. Dealio (free at dealio.com) automatically scours the Internet with its proprietary search engine, providing a list of deals in descending order by price, going "tens of thousands" of sites deep. It uses your Zip Code to estimate tax and shipping, and even shows current auctions. That automatic pop-up function, Dealio's biggest draw, is available only from the big sites for now (more will soon trigger it, a spokesman says). You can also begin a search from Dealio's navigation bar, built right into the browser.

It's a promising start that's riding a trend: Online shopping continues to surge, and one study found consumers save nearly 20 percent on average when comparison-shopping online, versus poking around at a local store.