Well - I've been in the park meeting friends and grilling a lot of meat drinking some beer - and now I'm addicted.
It's a very simple flyer - 2 motors no pitch elevator nor yaw rudder (there is a version with pitch elevator but not yet available here in switzerland). You gain height simply by accelerating and change directions by throttling one motor (so you can't change directions with disabled engine)
weights about ~20 gramms and comes with a remote control.
They write you can fly for 10 minutes (though i have the feeling that it's longer) and have to recharge for 30 minutes. You recharge directly at a small cable at the remote control.
The fact that they are so light weighted makes em indestructable if they crash
Wind is causing a bit of a challenge though and ending in the top of a high tree may happen at the beginning (solve problem with a stick and a long long string - bind string to stick, throw stick over branch with flyer and pull at both strings)
It's perfect for a barbecue session - fly some minutes then recharge. And if you're not sure about it - make a gift to some younger familymember and try it out sometime yourself
I'm sure i've wasted 30 bucks for ways bigger shit.
http://www.youtube.com/watch?v=hwB2YJ9b6ek
Another tip: if you really buy one - buy the sports flyer, it's the best.
Out of the box the flyers have too much boost - you have to stick a small centpiece under the nose with a tape - change centpiece to a bigger one if there is a lot of wind (I already had the problem having won height of about 50 meters and then started to realize that coming down with so much wind isn't easy when you don't want to land like half a mile away on some rooftop)
Last time i was in the park flying I've seen a couple embracing each other for a really long long time. The man was facing in my direction and I saw him follow my flyer on every turn while stroking his girlfriends back

The thing is called
X-Twin sports flyer
from silverlit