In Photoshop cs2 you can find a new feature named Vanish point.

If you want to replace same parts of your picture but you have problems with perspective, for exemple with bricked wall or wood floor, you can easly do it using the new option: Vanish point!

You can create your reference grid and use replacement tool (like clone tool) respecting your reference grid and your perspective.

Here 2 useful videotutorials to learn how to do it in deep:

• Photoshop support: Vanish point
• Watch and Learn: Vanish point

Enjoy it.