Hi there, my name is gary. I am travelling around the world next
month and would like to know if there are any websites which would
give me info on places to go to which are the "best kept secrets" of
the locals in that city. I am visiting Los Angeles, New york, London,
Paris, Capetown and Rome. In other words, i would like to know those
places and things to do which you dont usually find out about unless
you have a friend living in that particular city ie restaurants, night
clubs, beaches etc
that you never find out about on those "boring" tours. Thanks and good
luck.

Dear Gary, 

With all due respect to out esteemed commentator, Mayoarin, there is
one site that might just answer your prayers, and several others that
could also prove useful.

Virtual Tourist 
<http://www.virtualtourist.com/> 
Virtual Tourist is a "tour guide" written by locals and people who
have visited the place. They have an "off the beaten path" section for
each destination, where people write their tips on less "touristy"
places (see for example:
PARIS : Off the Beaten Path
<http://www.virtualtourist.com/travel/Europe/France/Ile_de_France/Paris-99080/Off_the_Beaten_Path-Paris-TG-C-1.html>).
In addition, they have forums, where people can ask locals all sorts
of questions, including peculiar wishes:

"I'll be in London in ~2 weeks and my itinerary won't allow for time
to go to Liverpool, any ideas on someting in London with a little
Beatle history."
("Beatle fan in London for a week", Virtual Tourist London Forums,
<http://forum.virtualtourist.com/1/discussion-195800-1-1-Travel-0-309228-London-discussion.html?wosid=u40N38BgNfijbI2lVteNwM>).

There are other sites and forums where you can meet locals (or people
who know the city well) and ask all sorts of questions.

TripAdvisor Forums
<http://www.tripadvisor.com/ForumHome> 

For example, from the NYC forum: 
"Please don't waste your time......... .......asking about trendy
places to eat in NYC. "
("Please don't waste your time.........", Trip Advisor NYC Forum,
<http://www.tripadvisor.com/ShowTopic-g60763-i5-k316004-Please_don_t_waste_your_time_-New_York_City_New_York.html>).

One place where you won't find many locals, but you will find many
tips on places off the beaten track is the Lonely Planet forums:

Thorn Tree Forums (Lonely Planet)
<http://thorntree.lonelyplanet.com/> 

These are the main Internet sites that might be helpful. However,
there are other ways to learn about the places where locals go to. For
example, you can buy a local entertainment magazine directed at locals
("TimeOut" or equivalent) and see what they suggest. Naturally, this
is going to be trickier in Rome or Paris, unless you speak Italian and
French (in general, I think from experience, getting along in "non
touristy" places in those cities will be difficult for someone who
doesn't speak the local language). Please note that the TimeOut
Internet site *is* directed at tourists, unlike their magazines. The
only exceptions are TimeOut London and New York, which are similar to
the print version.
TimeOut 
<http://www.timeout.com/> 

You can also try to know locals before you do there, through the
forums (especially Virtual Tourist), or forums that are not designated
for tourists, but for expats or people with common interests that you
share.

I hope this answers your question. Please contact me if you need any
clarification on this answer before you rate it.

Gary,
Unless a local from these places comments, any "best kept secrets"
wouldn't be such if they can be found here.  But perhaps you have a
couple of special interests that you would like to pursue in each
place that could direct a search for you.  Let us know.
Myoarin