Here are some of my favorite examples:
Matted frames are an easy way to add color to walls. I love the black and white photos that are set off, and don't compete with, the bright colors of the matte.
I love the black, white, blue, and yellow in this room--it completely works! And notice that the pictures are black and white too, but the wall is also accented by random pops of yellow. Love it!
Again with the black and white...but isn't this room pretty? And so calming...even though the picture arrangement isn't very "different," it still really works! The pictures are large enough to where your attention is drawn to the frames, and they are not ignored by the rest of the room.
Talk about unusual! But I love it. This wall is so different, yet so fun. And it's in an office space, so it's not an overpowering wall in the house, but a fun touch.
So COOL! I would love to put something like that in my dining room, especially if I hosted a lot.
This is essentially what I want a wall in my house to look like. (Except maybe with black frames.) But I love how absolutely busy this is! I get the feeling that I could stand and look at this wall for hours, and keep finding new things!
Wire strung on a wall, acting as a clothing line. I would love to implement this somewhere within my home. It would constantly change!