I've watched two (at different times). One touched down but it was over a half mile away and I couldn't see the damage it was doing, but got to watch the funnell.
The second, I heard coming and grabbed a six-pack of beer and sat on the back deck and watched as it came within about 300 - 400 yards from the house. It didn't touch ground, but was right at the very tops of the trees and it was bending about an acre-sized patch at a time almost 30 degrees, then as it moved on, those trees would stand back up and the next patch would get bent...it was really neat!
As for doing strange things, yes, they've been known very well to do them. A friend of mine when he was young watched through a window in his dad's home as the roof of a neighbor directly next to them (separated by about 40 yards) the roof got lifted off the house - the *whole* roof - and got set down between the two houses. It didn't have anything broken except for where it tore out from the nails...the roof could almost have been put right back on if there were a way to lift it as a whole.
My brother-in-law and his best friend were driving on some country hiway and saw a tornado coming. There was no place for them to go, so they pulled the car over into the little ditch on the side of the road, buckled up and put their heads between their knees and waited. The tornado picke the car up, turned it upside down, took it to the other side of the road and squashed it so that the thickest part of the car was 18 inches. Ny brother-in-law got the bridge of his nose mashed by the steering wheel and some bruises...his best friend died instantly because every single bone in his body was broken. Explain how *that* happens in the same car. Some wild shiite!