Desktop Software has come a long way in the last five years. Tracking used to be considered a 'high end' effect but know you can easily do on a laptop what you needed a workstation for not that long ago.
After Effects CS 6 adds a 3D Camera Tracker, and puts all the tracking/stabilizing options in the Tracking Panel. (Bring it up by selecting the Motion Tracking Workspace.)
There are 4 tracking options in the Tracker Panel, so lets take a look at what each one does and how/when to use them.
What it does: The 3D Camera Tracker lets you composite 3D elements with 2D footage. This is a current trend made popular by the titles in the TV Show 'Fringe'.
How it works: You select a 2D layer and click 'Track Camera'. The Camera Tracker analyzes the scene and creates track points.
You then move your cursor over them until you get a target that matches the plane. Click and choose 'Create Camera and Text'.
Then to add realism create a shadow by clicking and choose 'Create Shadow Catcher'. This creates a shadow catcher layer (shadow on a solid layer) and a light.
What it does: Automatically stabilizes shaky, handheld footage.
How it works: When you click 'Warp Stabilizer', the effect is processed in the background, so you can keep working while it analyzes and stabilizes the footage.
This works well to smooth out bumps in handheld tilts and pans and shooting handheld zoomed in. It isn't a miracle cure, so if you are handholding the camera in a car and there is a lot of bounce, it can't fix that.
Generally, Auto-Scale results up to 114% are usable, and much over that, the footage can look pixelated. The Default Stabilization uses 'Smooth Motion'. Use this when there is camera movement that you want to smooth out. Switch to 'No Motion' when you want the shot to be locked down. An Example of this is handholding a shot as still as you can when you don't have a tripod.
What it does: Commonly used to have text follow another object and replace phone & computer screens in commercials.
How it works: Click 'Track Motion' and it takes you to the Layer window. Track Point 1 appears, and move it to the object you want to follow. Th crosshair is the attach point (where the text will be positioned), the inner box is the feature region (put it around what you want to track, and the outer box is the search region. Click the analyze forward button and once it is done click 'Apply'. Click 'Ok' to the Track Options dialog that appears. This will take you back to the Composition window where you can see your track.
What it does: allows you to manually stabilize shaky, handheld footage.
How it works: Stabilize Motion works very similarly to 'Track Motion'.
Click 'Stabilize Motion' and it takes you to the Layer window. Track Point 1 appears, and move it to the object you want to stabilize. Click the analyze forward button and once it is done click 'Apply'. Click 'Ok' to the Track Options dialog that appears. This will take you back to the Composition window where you can see your track.
You will need to manually scale up the clip, as you will see black around the edges form the stabilization (the Warp Stabilizer does this by default.) Generally you will use the Warp Stabilizer instead of Stabilize Motion.