the turnstile industry is one of those industries you never think about, yet you interface with their products all the time. consider the following promotional statements from perey turnstiles ("the world's leader in turnstiles"):

"The mission of Perey Turnstiles, Inc., is the design, manufacture and sale of turnstiles, Drop Arm Stiles, Optical Stiles, gates and other "crowd management, admissions and access control mechanisms"."
...
"Saves space and increases throughput."
...
"The drop arm turnstile is designed to meet the spirit and the letter of the ADA regulations and the regulations of other nations."
...
"Our field upgradable turnstiles preserve your capital investment by eliminating the need for turnstile replacement despite future advancements in electronics."

and of their indoor high security turnstiles they note: "Ever been in a room with about $1,000,000,000? A foreign currency printer adds significant internal control to their plant security plan."

damn, i'm thinking of getting one of those installed in my apartment. i'd sleep better knowing any potential burglar would have to negotiate his way through that sucker.