So this year, I'll be raising herbs and a few tomato plants on even more limited real estate, on a shelf inside the southwest-facing windows. This way, I'll only be blocking my fire escape from the inside, which is perfectly legal.
Although I expect the greenhouse effect of the windows will give me a longer growing season, the amount of space I have is considerably smaller. But I recently found a great blog devoted to gardening in small spaces: Eight Square Meters is all about maximizing the yield of food that the author can grow on his 8-square-meter apartment balcony in Dublin, Ireland. The latest post has handy pollination tips; here's some advice on maximizing the yield from potato plants in boxes, and here's a photo of his "greenhouse," which actually looks like one of those dust-covers you'd use in a wardrobe.
Good stuff! I'll post some photos of my own indoor garden as soon as I get all of the plants potted and situated.