It is doubtful the inflatable rug will prove as necessary as the phone. Nonetheless, it earned the blessing of the U.S. Patent and Trademark Office, along with all manner of strange patents on display at Delphion’s Gallery of Obscure Patents. There, you can find details and images of unusual patents, from the bird diaper to the human slingshot machine, and historical patents, including the air bag, the flying machine and Velcro.

In fact, there is no shortage of wacky patents. For a virtual tour, the following sites can serve as your guides.

  • Ig Nobel Prizes. Celebrating the unusual in science, medicine and technology, the Ig Nobels are awarded to developments “that first make people laugh, then make them think.”
  • IP Funny. Written by “a couple of bloggers wanting to have some anonymous fun,” IP Funny tracks intellectual property humor. An oxymoron? Not based on some of the items, such as the cartoon version of a patent-prosecution flowchart or the condom that bears an unsettling resemblance to an ice cream scooper.
  • IPWatchdog Museum of Obscure Patents. Eugene Quinn Jr., a patent attorney and law professor in Syracuse, N.Y., each week highlights another obscure patent. His discoveries include the buttocks support device, flush toilet for dogs and the “beerbrella.”
  • KinsellaLaw. Stephan Kinsella, a patent attorney and blogger in Houston, has compiled an index of links to patent law resources. He includes links to some of the funny patents he has come across on the USPTO’s site. These include the pat-on-the-back apparatus and the Holy Bible trailer-hitch cover.
  • Patently Absurd features patents from the U.K. and other international sources. Inventions here include a ladder to enable spiders to climb out of a bathtub and a method of growing unicorns.
  • Patently Silly. While IP sites often are written by lawyers, this one is maintained by an engineer turned stand-up comedian. Every week, he sorts through new patents issued by the USPTO in search of ones he considers to be really weird, really cool or really scary. Among his finds: a slide-out deck for a recreational vehicle and a “device for determining and characterizing noises generated by mastication of food.”
  • Patent of the Week. Operated since 1996, this site has built a collection of more than 200 “strange, interesting, bizarre, inexplicable, wacky, useful and sometimes just plain perverted patents.” View them chronologically or by category.
  • PATEX’s Bizarre Patent Page features U.S. and Canadian patents. From north of the border comes the “reality mediator,” designed to prevent “the theft of visual attention or theft of mental visual processing resources.”
  • Purdue Law Offices, Wacky Patents. Patent attorneys in Toledo, Ohio, offer this modest collection of unusual patents, such as the parachute fire escape.
  • The Smoking Gun. Known for combing government archives for hidden documents, the folks at The Smoking Gun have compiled two collections of odd patent filings: Plumbing the Patent Files and Inspector Gadget Gizmos . Patents shown here cover inventions such as a wig-flipping device and ergonomic underwear.
  • Totally Absurd Inventions. Tracking “America’s goofiest patents” since 1997, it features a new invention each week and archives prior patents by title. True to its name, absurdity characterizes many of the inventions shown here, such as the dummy chicken farmer, a dummy programmed to patrol the coop at fixed intervals.
  • Wacky Patent of the Month. Devoted to recognizing remarkable and unconventional patented inventions; compiled by Florida patent attorney Edward Dutkiewicz. His finds include a device designed to provide an instant face lift and a locket to store chewing gum.
  • Wacky Patents. Patents+TMS, a Chicago law firm, offers this small collection of wacky patents, with no updates. It includes the motorized ice cream cone and the toe puppet.
  • Wacky Patents and Wacky Gadgets. In compiling this catalog of wacky patents, About.com has organized them by themes. Here, for example, you can find crucifix and Jesus patents, heart-shaped patents and clover and leprechaun patents.
  • Weird and Wonderful Patents, maintained by Ithaca, N.Y.’s Brown & Michaels, this site tracks what it describes, with tongue in cheek, as “vital advances to the state of the art.” It includes the proverbial better mousetrap, and a vest that lets you wear your pet hamster. This site is not regularly updated.