A roach clip is a clip, or other form of holder which is employed to hold onto the stub of a cigarette, usually a joint, that in this context is termed a roach, without burning the lips or fingers, and to facilitate passing the cigarette to others without dropping it.
The classic roach clip is the hemostat, a surgical tool resembling a lightweight needle-nose pliers with loop handles and a locking mechanism originally intended to clamp blood vessels closed during surgery. Their size (usually four to six inches in length) and shape (available with straight or bent tip) makes them ideal for smoking the roach without burning the smokers lips. They are popular enough as roach clips to be sold at " head shops".
Another popular type of roach clip is the alligator clip. These are generally smaller in size (one to three inches in length) than hemostats but, since they have a spring to hold onto the roach, it is easier to hold onto the roach.
An Amish Clip is a wooden clothespin that takes on a secondary role similar to that of the roach clip. However they are employed to hold the whole joint as well. These clips can be fabricated from any type of clothespin except plastic, although non-pine wood is preferred. Some Amish clips are fashioned with Dremel tools to have a more ergonomic feel, sometimes making it easier for ones lips to create a seal. This clip's naming, since usage was already common, is believed to have originated in Beaumont, Texas.
A Jefferson Airplane is a clip made by splitting a burnt-out paper match up to the head, putting the roach in between the split sections of the match, and holding the match by the end to smoke the roach or pass it to another.
Very common household items such as paperclips, tweezers and keys, can be utilised as Roach Clips; often used when the better alternatives listed above are unavailable. In outdoor settings, pine needles, twigs, or other items with the right flexibility can be employed. A very simple roach clip (used widely in the 1960s) can be made by tearing the end off of a book of matches and tightly rolling the cardboard into a cylinder, similar to a cigarette filter, that can hold the cigarette all the way down to the very end of the roach, thereby allowing the smoker to make use of every part of the cigarette. This is most often termed a "crutch" and allows the entire cigarette to be smoked without the risk of burnt fingers.
Naturally a real cigarette holder can be used as a roach clip.
There exists dovetail joints, which can completely eliminate the need for both the roach clip and the filter as holding devices. The dovetail cigarette has a flattened end that is curved slightly, usually between one and four centimeters. Although this rolling style is mainly for aesthetic value, it also provides room for the smoker's fingers to hold the cigarette after most of it has already burned.
When smoking cannabis, a buffer can be made by rolling another smokable material (most commonly tobacco) in the mouth-end of the joint.
The actual word "Roachclip" was granted as a registered trademark of the United States Patent and Trademark Office to Matthew Leitz on December 27, 2005. The official registered use is a "Toy roach with a clip attached so it may be worn as a pin or used as prank to scare a friend". Citation on uspto.gov - http://tess2.uspto.gov/bin/showfield?f=doc&state=a47p2h.2.1