I've always liked these types of shots.
I noticed 14 columns, double and twinned rainbows have 14 bands of color.
I used two layer modes, Grain merge (left group) and Soft light (right group).


Original Skyscraper photo

That creates a stunning vertigo effect.

odinbc: that's really cool, kudos for the idea! how did you make the grading?

I experimented with the Scissors tool but found the Free Select tool was better with the straight lines. I saved Channels for each column and then played with gradients and layer modes. The Gradient is FG to Transparent.

This is awesome. Stunning effect.

I toyed with the idea of using a grayscale version (right), but stayed with the building reflection colors. It was a tossup which one has a better look.

Really outstanding effect, Odin. My neck hurts from looking it up at it.

Did you tried a grading rotated of 90° ?
(colours changing with the distance from the base of the building )

Very good job. I like the idea of colouring the columns of the skyscrapers.

In which city is the one in the original photo located? It has every appearance of being infinitely tall.

I know it's in New Orleans, Lousiana. USA. It looks like it could be One Shell Square, with the photo taken from the first roof. The photo I used has the top cut off, so it's hard to tell.

I'm not sure what your technique is Photocomix, can you make an example?