Here are a few tools that we use to investigate the paranormal:

8mm Video Cam
Electromagnetic Field Meters -- detects
fluctuations in the EMF.  There are a lot
of different things can affect this
equipment, but it is theorized that
entities manifest themselves via the
EMF.
Infrared Digital Thermometer-- used to
detect thermal variations which some
believe can indicate the presence of a
ghost.
Digital Voice recorders-- Records EVP
sessions.  EVP--electronic voice
phenomenon can be a good indication
of the presence of ghosts or spirits.
Infrared Video Cameras -- It helps us
see in the dark and also detects things
that our eyes can't see.
Computers -- We use Gateway
computers, exclusively.  We have 3
Gateway laptops and 1 Gateway
Desktop.  We use them for logging,
analyzing, and storing data from
investigations.
DVD Camcorder-- used to record
areas of concern.  It allows us to
record hours of data to go over later.
Digital and 35 MM Cameras --
Provides photographic evidence.  Also
documents the investigation site.  
Note:  This group does not believe that
orbs are evidence of a haunting.
Check out the site below to get the equipment we use!
Audacity -- We use Audacity software
to analyze all our audio from our
investigations.  Click on the
headphones to get your own Free
download!
Wireless Audio Microphones.   Used
to monitor locations and records audio
to the laptop for EVP analysis
Motion Detectors -- Allows us to
secure a site, and potentially tracks
the movement of entities.
Wireless Weather Station-- Tracks the
indoor temperature and humidity
changes.