A new service is getting good press.
Otalo is a vacation rental search engine. Save time and search all the vacation home rental sites at once (kind of like Google, but for vacation rentals).
Just enter what you need once, and let Otalo search all the different rental sites for you. It’s easy to use and you can specify everything you want in a vacation home rental. You can save your favorite rental homes from all the different sites in one central place and share your list with friends and folks with whom you’re planning your vacation. Even if you’re not actively planning a vacation, you can just browse the world, looking at all the cool homes in exciting places. …
I have a lot of friends looking for vacation rentals through one service or another. Otalo wants to list EVERYTHING available in one place.
Rick McCharles 
Similar to Otalo.com, apartments.cazoodle.com is a rental apartment search engine that crawls thousands of rentals websites and indexes millions of apartments just like Google.