In Photoshop 5, I first selected the entire image, then used the Edit>Transform>Perspective tool. This gives you handles like the crop or scale tool, but is not contrained to a rectangle. I dragged the bottom handles directly sideways until the two main posts appeared parallel (109.4% of the original width). I then cropped the excess background this steps created. Unfortunately, I then noticed it needed about a 1 degree rotation; I try to always combine the crop and rotate steps by rotating the crop rectangle. Because this created more unwanted background, I just added a thick stroke in a contrasting color (not the one I'd recommend, but one you can see!) instead of cropping further.
(Tick ... tick ... tick ...) OK, that border looked pretty bad (I'm leaving it on the thumbnail so you can see) so I've selected the border with the magic wand, feathered the selection 8 pixels two times, then filled the resultant selection with white to create (what I hope is) a frosty effect, and then added a couple of pixels of black around the outside to make it show up on a white display page.
I've also been a little sloppy today, and have been re-saving the image in JPEG instead of Photoshop or TIFF format, so I'm sorry if the image quality has gone down a bit.
I agree this looks like a winter "stock photo" in the best sense -- I could easily see it on a greeting card or CD cover (I have one with a similar image I'll post when I can). Since it's not for a DPC entry, I wonder if you might want to try using a perspective-correction to make the two posts vertical, and even out the size of the windowpanes on the right.
Definitely picture perfect! The title suits this well. What an awesome view out your window, how lucky you are! The photo is so clear and crisp, I feel as if I'm there looking out.