There is a wide range of surveillance equipment on the market (and some of it you can make yourself if you have some basic knowledge about electronics). The types of equipment you can find range from the inexpensive and poorly made to expensive and professional. Sometimes you can be creative and use equipment for surveillance that was originally intended for another purpose. The items below could be illegal if used improperly, so always check with an attorney first before deciding to use any of them. We do not represent, or endorse, any of the companies/links listed.
Keystroke capture: The personal computer is an excellent tool for the cheater to use since they can shop for a new lover and communicate with them in secrecy. One tool to find out what they are typing is a keystroke logger. This device is quickly inserted between the keyboard plug and the computer, or plugs into a USB port, and will quietly record all of the things your suspect is typing on the computer. Later, you can take this device and download a log of their activity. This is very handy, but does have the disadvantage of only logging one side of a conversation (if they are using a messenging program) or email.
www.recwi.com
Screen logger: Another valuable tool is a screen logger (sometimes referred to as computer spy software). This program is installed on your suspect's computer and it secretly records everything that they see on the computer screen. This information is either stored on their computer in a hidden file, that you can review later, or sent to a predetermined email address. This software can be useful to detect if they are looking at dating sites, chatting with others, or looking at porn, but you must have access to their computer in order to install the software.
Computer video surveillance: If you are away from home and want to see what your significant other is up to, then secret computer video surveillance is what you need. This software, which operates hidden from the computer user, allows you to log in from a remote location and see everything that is going on within view of an attached web camera. So if your lover invites some "company" over for a little fun while you're out, then you'll catch everything from the comfort of the local coffee shop.
GPS Tracking: With the popularity of GPS, many products have been introduced that allow you to track the whereabouts of your significant other in real time or for review later. One device is a GPS logger! This small device can be hidden in your suspect's vehicle and it will track every road they drive on and log the time as well. So, if the driver stops at their lovers house, the GPS logger will indicate the stop and start times to give you an indication of how long they were there. This is a great tool to determine if they are being honest when they say they're just going to the gym. Care must be taken to ensure that the logger has a fairly good view of the sky in order to receive the GPS signal. Some good spots to hide them are under the front dashboard or near the rear window of the car. It's best to first test the unit yourself before deploying it in actual surveillance.
Trackstick.com
Hidden cameras: If you believe that your suspected cheater is having an affair in your own house, then you may want to consider deploying hidden video surveillance cameras. This can be a costly option, but there are some inexpensive devices that are on the market. Firstly, you can find almost anything with a hidden camera in it (clock radios, lamps, smoke detectors, bags, mens ties, hats, fire sprinkler heads, screws, etc), but one thing you must consider is where are you going to record the video. All of these hidden cameras require either a digital video recorder or VCR with the video being delivered by wire or wireless (radio). This kind of setup is costly and requires some serious planning since you have to hide the sometimes bulky recording equipment and set up the hidden camera. For those of you who think that you can find any hidden camera, think again! Many of these items use pinhole camera lenses that are virtually impossible to detect. Look on your wall at home and see how many holes that are left behind from nails that once hung pictures. A camera could be hidden behind a hole of that same diameter that would display a perfect image of the room in question. The entire size of this pinhole camera (pictured below) is the size of your thumbnail!
An alternative is to use a compact camera and flash memory that is contained in one unit (pictured below). This small device is fairly inexpensive and can be hidden in many ordinary items.
www.geeks.com
Regardless of which camera you decide to purchase, make sure you compare the frame rates, lux (ability to be used in the dark), resolution, and length of time you can record. The standard frame rate for television is 30 fps and the lower the lux, the better it is at night. To improve night viewing, use a black and white video camera with an infrared light.
Surveillance cameras
Communications
Vehicles
Phone apps: To track text and phone calls