To "Phelps" a joint or bowl of marijuana is to finish it in under one minute. After finishing, the person who takes the final hit must declare "I told you guys... under a minute" This term stems from Michael Phelp's Rosetta Stone ad in which he completes the ad in under a minute and says the aforementioned quote. This is combined with the new information that Phelps is a raging potaholic.
We're late for the movie man! Phelps that shit! *59 seconds later* "I told you guys... under a minute."
While smoking a joint or bowl of marijuana, if someone says the phrase "Sean Connery says schmoke it" (in his accent of course) then the amount that is left must be finished by those who participated when the joint or bowl was lit. This is referred to as "calling Sean Connery." This term is classically used only once per day among a group.
Travvy: Maaaaan...... I'm too baked, i'm done.
Timmy: "Sean Connery says schmoke it"
Travvy: Well, you've got to obey the Sean, hand it back.