I was staring at my window last night, and daydreaming (nightdreaming?) about filling it with shapes. Suddenly, I was struck with inspiration for a new type of puzzle! Here's a fairly easy instance:
Pack the colored polyominoes into the white area, without rotating them, so that they fill it perfectly.
What's that? The green piece can't fit, you say? Oh right, I forgot to mention: The gray walls are portals. Any piece that would normally overlap a gray wall goes through it entirely, as if there were no space there at all. The gray border around the puzzle loops, as well - pieces that would stick off the right side of the board reappear at the left, and so on.
To demonstrate, here's an example packing:
Notice how the blue block warps from C1 to C3, across the wall at C2.