Steps to get OAuth Playground working for Google Latiude

Step 1: You must have a domain registered with Google here:https://www.google.com/accounts/ManageDomains
This is how Google identifies your application, even if it's an installed program, not a web app. Once your domain is registered, take note of your OAuth Consumer Key and OAuth Consumer Secret, you'll need  them later.

You can also register at google appengine if your creating an application and don't have a domain .

 Step 2: Now you can go to the OAuth Playground:http://googlecodesamples.com/oauth_playground/

 Scope: Nothing checked  

 Input your own:https://www.googleapis.com/auth/latitude

 Modify OAuth Parameters

 oauth_signature_method: HMAC-SHA1

 oauth_consumer_key: <yours from domain registration>

 consumer secret: <yours from domain registration>

 oauth_token_secret: <blank>

 oauth_token: <blank>

 Step 3 :

 Click "Request Token."  oauth_token_secret and oauth_token are now
 filled in, and you have an unauthorized request token.

Step 4 :

 Google Latitude uses a different Authorization endpoint than other
 Google services!
When you click the "Authorize" button, your browser will redirect tohttps://www.google.com/accounts/OAuthAuthorizeToken&oauth_token=token....
YOU MUST NOW CHANGE THE URL

http://www.google.com/latitude/apps/OAuthAuthorizeToken?domain=example.com&oauth_token=token
Keep the oauth_token parameter the same, but change the URL, and add

the Latitude-specific parameters discussed in the "Using REST"
document:http://code.google.com/apis/latitude/v1/using_rest.html#auth
Once you're on that Authorization Service page, click "Grant access."
You'll be redirected back to OAuth Playground

Step 5:
You can now exchange your Authorized Request Token for an Access
Token. Click the "Access Token" button. 

If it fails just redo the steps and I think it should be fine .

Step 6 :

In the Drop down box Slect Get Option and enter the URL

https://www.googleapis.com/latitude/v1/currentLocation

This should return you a JSON result that will return your current location .

Actually Google gives you different options to set location 

1) Either through a GPS enabled mobile phone or 

2) You can set it manually using the iGoogle Latitude widget .

I hope this will be helpful for someone who is creating Apps with

Google Latitude Api

Thanks,,,

Vaishakh