We all know that iTunes and the Mac App Store are available from any web browser, but they don't exactly allow you to "browse" the store like you can in iTunes. If you want the flexibility of a tabbed web browser with the browsing ability of iTunes, you can get the best of both worlds with a little drag-and-drop action.
Let's say you find a number of apps you want to check out while browsing through the iTunes Store. You can't open them in tabs in iTunes itself, but you can click and drag the app icons into your web browser. Each icon you drag over will open the corresponding app in its own tab, so you can open a bunch at once and compare reviews without having to repeatedly click the "back" button or perform new searches. It's a simple but handy tip to remember when you're in the middle of an intense app-shopping session.
Drag and drop Mac App Store icons to make up for its lack of tabbed browsing [Finer Things in Tech via Mac OS X Hints]