Recently GE Fanuc did a story on Robotic Parking Systems as a solution for parking in urban envioronments. Here's an excerpt:

"Matching the theme of GE's ecomagination initiative and a commitment to invest in innovative solutions to solve environmental challenges, Robotic Parking Systems Inc. has developed automated car parking facilities that double the storage capacity of a conventional multi-story car park... Per car park space, the automated parking and retrieval systems typically offer savings of between 30% and 40% in terms of development costs and savings of between 30% and 40% in running costs thanks to the savings in volume of over 50%."

Click here to read the full story or to download the pdf file.