Creating flying is back! ...but now on Vincent. Rather than the IC2 fuel jetpack, any pair of boots will work.
To activate creative flying, you must build a beacon made of pure diamond. Only one level is needed, but more levels will give you a larger radius of effect for the flying.
Sneak and right click the beacon to activate flying mode. Double tap your jump key to fly.
Your boots will degrade over time while you are suspended in the air. Iron and chainmail boots should last for approximately an hour (real life time), but leather and diamond boots will last for shorter and longer durations, respectively. You will be provided feather falling on the boots to reduce damage from falling should the effect wear off.