You can find a wide variety of security motion detectors online The web should be the first place that you look to purchase motion detectors.

I recommend:  The Home Security Store offers a wide variety of motion detectors including: infrared, ceiling mount, pet immune, wireless or outdoor motion detectors. Smarthome also offers offers you motion detectors that would be suitable as business motion detectors. GadgetShack.com also offers a variety of security motion detectors.

Go one step further than run-of-the-mill motion sensors Consider spending a bit more money or a more high-tech system or one that links to other gadgets such a security camera.

I recommend:  SecurityIdeas.com offers Optex indoor & outdoor motion detectors. These motion detection products are designed to trigger switchers, multiplexers and time lapse recorders when there is motion. The output relay will turn on a specific camera and turn the recorder on real time mode. Check out the Siemens motion detection system. Its mirrored design gives you uniform sensitivity throughout the area that it covers, thus eliminating your over- or under-sensitive zones.

Install your motion detection equipment like a pro Make sure that you are installing your motion detection equipment properly.

I recommend:  Check out the Lowe's "how-to" page on installing motion detection products. The Do It Yourself (DIY) network also gives you a tutorial on installing motion sensors. The tutorial was designed for residential use, but could easily be translated for business installation.