Sites like Orbitz and Expedia make it easy to compare plane tickets from a variety of airlines.

Now you can do the same for your other purchases.

PriceSpider.com shows users the real-time best prices from online retailers of everything from televisions to toys. What's more, you can get price alerts by email and even see a six-month price history so you can decide if that "deal" is really so great.

The selection of products on the site isn't that extensive, but the range of prices on many products makes PriceSpider an indispensable place to start looking. For example, PriceSpider reported available online prices between $255 and $600 on one digital camera when I explored the site.

With a laptop on its last legs, I now know where I'll begin my search for a replacement.