Here lost of websites listing properties on google map by radius search. zillow.com is one of the premier example. In India they are using nbook.in to search properties and to find houses. This is too hard to understand because Trulia.com is not available in India
Check out Zillow.com...
Best though, select an agent who has website with access to all of the "real" data, updated immediately, unlike syndicated websites...I mean access to MLS which will allow for any type of search. I'm sure you have many great agents with such access in your area.
Hope this helps,
Beachfront Realty, Inc.
Good question. Something I can take back and suggest we update for our user. In the meantime, our iPhone app has the ability to search up to a 30 mile radius.
Thanks for asking a really useful question.
Social Media Guru at Trulia