Here’s a product that follows the guidelines of KISS (Keep It Simple Stupid). It’s a camera level in simple low tech design that can save you hours of post processing by getting your horizontal and vertical lines right in-camera.
Photojojo’s Level Camera Cube is a 1″ x 1″ x 1″ cube that slides into your camera’s hot shoe with a 3-axis level allowing you to shoot both horizontally and vertically.
Once the cube is attached to your camera, use it to level out your shots by pointing at your subject, aligning the bubbles of the cube to set up a straight and narrow frame, and then click away.
The Level Camera Cube is available from Photojojo for $15. But get two, and they’ll throw in a discount and slash the price down to $25.
In post, if your shot’s still aren’t perfect, you can use the new Photoshop CS6 feature “Adaptive Wide Angle Filter”.