First of all i would like to thank to "Mr.Matthias" for the valuable
information.

        I too faced the same problem like you people, now i got the
solution for this.
        The reason behind this problem is, Android has announced on oct 22nd
2008 that, If your application uses one or more Mapview elements, you
will need to register your application with the Google Maps service
and obtain a Maps API Key, before your MapView(s) will be able to
retrieve data from Google Maps. To do so, you supply an MD5
fingerprint of your signer certificate to the Maps service.

        I have gone through the process, Now i am getting the 'MAP'. The
procedure i followed to get the Map is as follows,

        While registering for android Maps, we need to give your applications
"MD5 Fingerprint" to get the API key,

        I)      First of all we need to give our application MD5 Fingerprint while
signingup the key
                http://code.google.com/android/maps-api-signup.html

        II) To find your Application MD5 Fingerprint of the SDK Debug
Certificate follow these steps.

                1) You have to go to your keystore first, to find you keystore path
in Eclipse :
                        "debug keystore" is located at select Windows > Prefs > Android >
Build to check the full path

                        for eg:- The path may vary fo r different operiating systems, like
following for Vista,xp and linux.
                        Windows Vista: C:\Users\<user>\AppData\Local\Android\debug.keystore
                        Windows XP: C:\Documents and Settings\<user>\Local Settings
\Application Data\Android\debug.keystore
                        OS X and Linux: ~/.android/debug.keystore

                2) To goto that particular path you found in the first step. Now,
goto command prompt and
                    for eg:-
                        "C:\Users\<user>> cd C:\Users\<user>\AppData\Local\Android"   it
will go to that path as follows
                        C:\Users\<user>\AppData\Local\Android>

                3) After second step, at command prompt, Here is an example of a
Keytool command that generates an MD5 certificate fingerprint for the
key alias_name in the keystore my-release-key.keystore

                        for eg:- C:\Users\<user>\AppData\Local\Android>keytool -list -alias
androiddebugkey -keystore debug.keystore -storepass android -keypass
android

                        it will generate you applications "fingerprint". Now copy this
"fingerprint" to the api key signup.

                4) To register for a Maps API Key, follow these steps:
                        load this page in a browser: http://code.google.com/android/maps-api-signup.html

                        If you don't have a Google account, use the link on the page to set
one up.
                        Read the Android Maps API Terms of Service carefully. If you agree
to the terms, indicate so using the checkbox on the screen.
                        Paste the MD5 certificate fingerprint of the certificate that you
are registering into the appropriate form field.
                        Click "Generate API Key"

                       You will get the apiKey, copy that key to your MapView.xml