I recently bought a pair of Icarus Wings for my avatar on Second Life. They're better wings than most in that they actually fly the avatar, not just look pretty and go along for the ride. They don't rely on regular Fly mode, meaning I can fly in no-fly sims. They fly by gliding with the up arrow key with occasional flaps of the wings using Page Up.

But sometimes the Icarus Wings will kick in with insane, uncontrollable bursts of speed and send me into cliffsides and trees before I know what's happening.