Owning a geiger counter as a lay person is not as weird as one would think.  Many people have one!  What type of people own geiger counters?

Obviously there are professionals.  Radiologists, Reactor Workers, Hazmat Specialists, Dept. of Homeland Security personel, Health Physicists, Uranium Prospectors, Geologists, Siesmologists, etc.  A geiger counter, ion chamber, scintillator or dosimeter  may be an integral part of their daily worklife.  However, a large group of people may own radiation detectors who don't actually need one.   

Parapsychologists may use radiation detectors in their investigations.  However, I have personally seen some well known psychic investigators call a CDV 715 high range ion chamber a geiger counter (see http://www.radiationfinder.com/Counters_Ratemeters_Etc).  If a ghost where to actually emit that much radiation, the psychic investigator would soon be a ghost!  The key is knowing your equipment, know what it measures, and have a general idea of how it works.    

One individual I know in the kitchen cabinet industry is very concerned about granite countertops, not only does he have a geiger counter, he has a scintillator, and a gamma ray multichannel analyser (it can tell what radionuclieds are found in the granite)!  He understands how the equipment works and has a good understanding of the measurements and what they mean.  His primary concern is the safety of his employees as well as the safety of his customers. 

Survivalists may want a geiger counter.  Of course it would be for protection in an End of The World scenario, to check food and to avoid contaminated areas.  This breed has significantly changed from the Cold War homeowner with a bomb shelter to those that may shun society and live in the woods or desert, away from cities.  Obviously, not everyone who is a survialist lives that way.  Many people just want to have safety equipment and foodstuffs if something catastrophic happens.   

Another big group of people are collectors.  There are alot of people who collect for many different reasons.  Maybe they have fond memories of the days of "Burt the Turtle" and "Duck and Cover" (see http://www.conelrad.com/index.php ).  Others may just be movie and buffs and have fond memories of the "Twilight Zone" or "I love Lucy," or the many 1950's and 1960's science fiction movies that showpieced some of the highest tech radiation equipment of that era.  There are many collectors that enjoy restoring old geiger counters from the uranium boom days to working peices of history.  Some collectors will "hotrod" them, and make them better than they ever were.

Amature scientists often will have a geiger counter, or other radiation detector.  Many can do quite a few experiments with them, as well as use them in their experiments.  There are actually a few people who have made x-ray machines or Farnsworth Fusors (a device that may be producing nuclear fusion reactions), who may need an Ion Chamber to determine if their X-ray machine is working and measure the radiation, or in the case of someone building a Farnsworth Fusor they may need to determine if their device is generating X-rays, or if it is working properly they need a neutron detector to find out if it is actually working.

Mineral collectors are of course one of the best candidates for radiation detection equipment.  There are many minerals that may be prized for their beauty as well as their radioactive properties.  A geiger counter is a natural choice for finding uranium or thorium minerals.  

One group of people that would be considered by some to be quite strange would be the collectors of radioactive antiques.  Many objects are prized by collectors for their radioactive qualities, vacuum tubes, radium dialed clocks, watches and aircraft guages, vaseline glass glassware, old radon revigorators, patent medicines, illuminated electric switches, as well as toys and medical devices.  One of the most prized posessions are luminous bridge markers, or sometimes called deck markers or paratrooper disks.  These items where a very simple glow in the dark disc used for safety purposes.  Because of their large size, and amount of radium used to cause the paint to glow, they are quite radioactive.  Not enough to kill, but significant enough to be detected from some distance with a geiger counter. 

Collectors of radioactive minerals or antiques need to take special care of their collections. Special care needs to be taken to avoid contamination of ones home, or to avoid radon gas that may be given off.  Good ventililation, sealed containers or bags, or even lead lined or lead storage containers are used by these collectors for person radiation protection.

With the recent problems in Japan, the meltdown (yes, there are good indications that a meltdown has or is at the time I am writing this) of the reactors of Tepco, at the Fukushima Daiichi power plant there are thousands if not millions of average people who would like to own a geiger counter.  People who want to check food, the air, their clothes, shoes and even worse their bodies to test for contamination from the radioactive plume of smoke and from seawater.  I suspect that many people wish they had or could buy a geiger counter at this time.  Those who live near nuclear powerplants may have the desire to posess a geiger counter for their own personal safety.  Unfortunately if you live in the affected areas, buying one after the disaster may create undue worry.  After all, you didn't have one before the disaster, so what is normal background radiation?  Obviously a geiger counter could indicate contamination of food, water and personal possesions, and may be a necessity for some in Japan for years to come.   

The last and best reason is they can be fun to own!  They can be a great addition to any halloween costume, and a great conversation starter, or just a bizare addition to your office, cubicle or desk.