Would anyone be interested in trying out the RPG system "Mythic"? It's so freeform that it can be demoed with little or no preparation, given players eager to make stuff up as they go along.
Worst thing about it: you need
http://3.bp.blogspot.com/-kaUOGKCX9Yw/US7WeZvl48I/AAAAAAAAAfM/cIYCJCDG6Kc/s1600/MythicFate.PNG as a reference chart, the meaning just being "find your own skill level on the left, then decide on a difficulty on the bottom, then try to roll <= the number given". Everything is basically in terms of asking yes/no questions like "is there any sign of trouble?" or "do I hit the goblin?" with a chance of forcing a roll on the "give me two interesting words like 'threaten/home' to inspire a random event" chart. The system can also be used as a GM emulator to generate ideas and scenes within any other system.
Character design can be done on the fly with nothing more than a vague concept. Here's a sample sheet for a mysterious character:
V***** THE WIZARD
A solitary mage specialized in fire and enchantment spells, who dabbles in transformation magic despite frequent mishaps with it. He prides himself on organization and punctuality, and is stubborn, frugal, and hard-working.
* ATTRIBUTES *
Strength Average
Agility Average
Reflex Above Avg
IQ High
Intuition High
Willpower Exceptional
Toughness (Strength+Will/2): Above Avg (+1 for armor)
* ABILITIES *
Spell-casting Average
Lore: Magic Average
Enchanting Above Avg
Mace/Hammer Below Avg
* EQUIPMENT *
-Mage Mallet: Light and sturdy for its size. Can strike with a red-hot blow.
-Robes: Enchanted for toughness and fire/alchemical resistance, +1 armor. +2 vs. fire.
-Treehouse laboratory: Well organized and equipped as an enchanter's laboratory.
* SPECIAL *
-Uncurse: V***** is all too experienced at undoing the effects of curses/spell mishaps, and gets a +1 RS to all rolls to try to undo these, if he can take an hour or two to study.
-Favor Points: 50 [Spend to change % die rolls]
Any interest? This can be done whenever.