Time it takes: 30 minutes
Before you buy anything on the Web (or at a mall), spend a few minutes at a comparison shopping site. Shopping.com and Shopzilla.com both scour the Net for bargains at a large number of online stores, but their results can vary. Looking to buy a Garmin GPS for your car? Shopping.com found one from a top retailer for $357.95; Shopzilla's find was $212.54.