Here's a game that I played recently on this web-site that featured several study-like variations in the endgame. Play over the different continuations branching out around move 57... they include a (forced) under-promotion to a Bishop, a promotion to an en-prise Queen in order to gain a tempo, and a line where I sac my last piece (a Rook) in order to draw the opponent's Rook to a square from which it cannot harrass my King:
http://www.chess.com/forum/view/game-showcase/a-study-like-endgame
Here's one that I still am not sure is a win or a draw for black from one of my OTB games.
Somehow I held this position for, I would guess, 50-100 moves with less than a minute on the clock, playing off the 5 second delay. He had a half hour, though, but he used up so much of his of time that he lost on time! I think that this is a draw, since if black comes around to try to take my pawn, I can always counterattack his. For example, if Ka4, Na1! coming to c2. Ka3 Nc2+ Kxa2 Nxb4+! draw. Still, black might have a way to win, I really don't know.
Why can't Black move his King in the first post?
In the first position why not 2...Be7 (edit, ok I see now, same idea).
Looking on my own, in the mainline it seems 3.Kf3 also wins.
3.Kf3 Kh4 4.Kg2 g4 5.Bf2+ Kh5 6.Kg3 gxh3 7.Kxh3 and the king infiltrates. The computer doesn't agree for about a dozen more moves but it eventually agrees. Maybe this sort of try is unnecessarily complicated. The zugzwang maneuvers are study like.
---------------------------------------------------------
In the 2nd position 1.h5 is a simple book win. The only way to draw the f and g pawns is to prevent white's move f5 (after that there is no fortress) and after 1.h5 (simply threatening to capture and then play f5) 1...gxh5 2.Kxh5 it's impossible to prevent white from playing f5 and black can resign, no need to calculate anything fancy as in the diagram solution.
Here are 2 positions I played in a recent tournament:
The first is not the actual position in the game. The point of the kingside pieces is that if black's king moves, he will soon lose (this was achieved differently in the actual game). This was played as black against a grandmaster. The second position was me playing White against a master-level player.