You'll run into three basic types of mounts for your home theater display:
Flat-panel mounts: These are designed predominantly for plasma displays and LCDs. You will find versions for ceiling, wall, and pole mounts (for floor-based mounting). Flat-panel mounts can be static, pitch, and swing mounts. Static mounts don't move. Pitch mounts pivot the display up and down. Swing mounts articulate up and down and side-to-side.
Projector mounts: Projector mounts are generally based around one design, but they tend to come with a lot of accessories that let you use the mount on a ceiling or wall, deal with a drop ceiling, and so on.
Automated solutions: For superslick installations, projector ceiling lifts and pop-up plasma lifts hide your gear when not in use. You can also automate swing arms so that, with the press of a button, your TV swings into a preprogrammed position.
If you're thinking about an automated solution, there's a whole different level of expertise typically required in order to manage the environmental, electrical, and other design elements of a successful implementation. These are generally not do-it-yourself projects. If you're looking for help mounting a display, check with your home theater dealer, look on the mount manufacturer's Web site, or look for installers in the "homeowners" section on the CEDIA (Custom Electronic Design and Installation Association) Web site at