That last one would make a awesome album cover and sorta reminds me a little bit of a Dead Soul Tribe allbum cover(I think)

how is this done?
^Two shots. One of him sitting on a chair, one shot without the chair. Then it's just a matter of putting the two shots in photoshop, and using the mask to hide the said chair.
I see a slight blurring under his arse. I think he's floating on gas power. Did it rip a hole in your pants?
I was sitting on my coffee table. I took one shot of me sitting on the coffee table, and another without me and no coffee table. The trick all comes in the shadow.

For the shadow I made another layer. I selected me, made it completely black. Then I made it opaque to a degree, skewed, and faded it. Without the shadow, the shot is worth nothing.