We've published a variety of hints over the years about opening a Terminal window that's already focused on the folder of your choosing. But Hints reader ceej discovered that Apple's built a new Service into Lion that can make this task even simpler.
To enable the Service, launch System Preferences and click on Keyboard. From the Keyboard Shortcuts tab, choose Services on the list at left, and then choose New Terminal at Folder (or New Terminal Tab at Folder). While you're here, you can add a keyboard shortcut by double-clicking in the whitespace along the right margin of the Services list and choosing a new key combo.
Now, when you Control-click (right-click) on a folder in the Finder, your new Terminal Service should appear near the bottom of the contextual menu. Use that new menu option—or your new keyboard shortcut—and Terminal will open a new window (or tab) focused right on the folder you chose.