Here's the links to the Craigslist and Kiji Geek sites where you can search the Craigslist and Kiji of all citys at once!.
http://kijigeek.com/us/
http://craigslist.extads.com/
These are the US sites..
If you're in Canada or elsewhere, on the Kiji one at least you can click on the upper flags to access your country's site..
Good luck!.
~ Pete