Rapid Fire is a game originating with BBLiveShow in which someone (usually Justin Robert Young) is given an either-or option by the chat room and he rapidly fires back with his choice. For example, if someone were to ask, "PC or Mac", JRY would fire back with "PC!"
Rapid Fire usually takes place at the start of the after show while Brian disappears briefly to take care of other business. On occasion, particularly in early NSFW episodes, other hosts have joined Justin in the Rapid Fire process which has resulted in it not being so rapid and a bit of a trainwreck.
In January 2010, Justin started doing occasional Rapid Fire via Twitter. People could send him a choice within an announced 24 hour period and he'd tweet back his choice. Some have referred to this as "Twitter Fire" since the Twitter replies aren't always that rapid.
On February 15, 2010, Justin set up a Formspring account to answer Rapid Fire-style questions.