I actually learned the secret of farting inconspicuously around other people, you need to let the bubble go slowly in a constant and controlled stream until you're out of gas. It'll pass silently and since you're just one person in a group of people, don't act suspicious and nobody will know you did it. Sadly enough that was probably one of the most [i]useful[/i] things I learned in high school. Not the most valuable by any means, but pretty high up on the list of most practical.