Want to convince someone more easily? Buy them a large StarCrack latte before you start your pitch.
Roxanne Khamsi at Newscientist.com reports on a study that seems to show that coffee makes people more open minded. The effect doesn't stem from coffee making people more suggestible. Instead, it seems to be that coffee improves cognitive function and mental ability. So, coffee might be even more important if your argument requires more thought.
Next thing you know, coffee sellers will be using this in their advertising.
HT: Abnormal Returns