On the second one especially, the black appears rather navy. It's a simple black level fix in just about any photo editing or managing program. It might just be my monitor though, so wait and see if anyone else comments on me before you go toying around with your images, which are good by the way.
I love the 2nd one - and yes the background has a bit of a cast, but not a lot.
I hope you dont mind, but I played with it a bit, removing the cast, adding a bit of Lab Saturation colour (it always amazes me how much colour there is lurking in images) and contrast - do you like it the idea?
I like your edit, the color of the actual fountain is more interesting i think, nice edit.
for number three the exposure was set at 30 seconds at f25.
thanks for the great comments everyone.
I think its my monitor, on my macbook pro which i use to edit my images with cs3, it seems to be darker, i look at the same images on our pc computer in our house and i can notice the colors being off. I guess i need to figure out how to fix it so i can see the difference, otherwise it would be quite a waste to have cs3 and not even realizing my colors are off.