Have you got an iPhone? If you do then you are likely to know all about 'apps'. Rightmove have created an app that uses the GPS in your phone to discover exactly where you are on the planet then serve up a listing, with photos, of the properties listed on the site that are very close to you and up to about a mile away. I downloaded it from iTunes the other day while I was waiting for an applicant to show up for a viewing and, lo and behold, the house I was about to show was top of the list!
Have a look here http://www.rightmove.co.uk/property-to-you/iphone-application