Colorado law says cannabis must be sold in rooms that can't be seen from outside, so the real business happens in an interior room. A helpful and knowledgeable "budtender" — a guy in his 20s or 30s, typically, who has submitted to a state background check — guides you through the selections.

He may be Denver's most famous pothead, but William Breathes isn't his real name. As a registered medical marijuana patient — for a chronic stomach condition — he has to show ID every time he goes into a dispensary, and fears he'd get special treatment if the "budtenders" knew they were serving the influential critic.

Prospective members had to bring doctors' notes, diagnoses and identification. Club organizers called doctors to confirm the documents were legitimate before issuing computer-generated ID cards with photos and a bar-code strip.

The next step was purchasing the pot from "bud tender" Randi Webster, who had six types available, from Mexican-grown to top-quality California "quad."