Pictures from Meridiani planum
These were each assembled from 3 grayscale images that were combined into one RGB image with Photoshop.
The original images are on NASAs website here

horta tends its eggs
Horta:  A silicon based lifeform, tending its eggs.  If you don't believe this, just go to the NASA website
raw pancam images for sol 219.
500x500   156 kbytes
my 1st mars image
This is my first image of the surface of Mars.
I was so excited about seeing the colors that  I forgot to note when or where it is from.
500x500   157 kbytes
sol 42
Sol 42:  Opportunity was still inside eagle crater.  I think this is the blueberry bowl.
The colors are very exagerated, but the layering that you can see in the rocks because of the enhancement is real.
500x1000   80 kbytes
sol 118
Sol 118:  This is from outside of Endurance crater.  Does it  look like some kind of
                mudflow or what?  I have seen no comments about what this might be.
500x500  149 kbytes
sol 132
Sol 132:  This is from inside of  Endurance crater.  There seem to be some strange looking
               rocks near the bottom.
500x500  89 kbytes
there is also a full resolution version 1024x1024   622 kbytes  HERE