There has been some interesting projects being developed in this space lately. Probably the more accessible ones at the moment are those that use a Google Maps/Flickr Mashup such as these ones
Paul Hogans's proof of concept mashup for the Powerhouse

http://www.paulhagon.com/blog/2008/08/19/powerhouse-street-view-mashup/
Or this one Sepiatown that Seb Chan mentioned in his recent TEDx Sydney Talk

http://www.sepiatown.com/index
While these are great sites I wanted to find some examples where there was more of a User Generated Content approach so people could add their own stories, photos and comments easily.
One project I really loved is this one which is Facebook based but seems to have created some really greal dialogue around the places is by Dan Blank who posted 175 photos and his memories on Facebook after a trip to his hometown in Howell, New Jersey. He had 700 comments then pulled the dialogue back into his blog
http://danblank.com/blog/2010/01/26/how-i-used-facebook-to-unearth-a-towns-history/
And of course the wonderful work of Priscilla Davies from our very own ABC on Black Saturday which mapped stories from the huge bushfires in Victoria in 2009

http://www.abc.net.au/innovation/blacksaturday/default.htm#/timeline/map/chapter/1