Okay, I just re-read my original instructions in the link posted by wickedclown and the only thing I'd change is that the "cooking" process might take a little longer than 90-120secs, probably closer to 4 minutes, but it has to be down SLOWLY, EVENLY, and GENTLY so you don't burn the cigarette paper or completely decompose your cocaine.
The idea, as explained so beautifully by Roches, is to gently vapourize the cocaine hcl so that it soaks the tobacco and makes the coke easily smokable upon re-ignition. The trouble with smoking acid salts is not necessarily that their ignition temperatures are too high, but that there ignition temperatures are too close to their decomposition temperatures. In other words, by the time you get the shit hot enough to smoke, you're wasting it. The "cooking" process of powder cocaine in a cigarette or joint is an ingenious method of using this instability to the advantages of people who like to get high.
Stitescloud, there is a kitchen crack recipe provided in that same link FYI.
And Mudder a' Christ please stop all this "numb lips" talk. That is some of the stupidest shit I have ever heard, it's fucking embarassing to see MODS of this forum say poopie such as this, and for anyone who claims that numb lips and a placebo high are the only effects of smoking cocaine, I can GUARAN-FUCKIN-TEE you this person has never smoked cocaine properly.