We are trying to send the notification to an Android App about any event generated in salesfoece(Like creating an account), using the Google's GCM(Google Cloud Messaging).
Here is the link that tell about the GCM ,

http://developer.android.com/guide/google/gcm/gs.html#android-app

I m using Eclipse for creating Android App and my GCM server gave me the SenderID and API key.

But the problem is , How can I use Salesforce as my 3rd Party Application,from where the notifications are generated.

show image of contact in formula field in contact detail page(image is stored in notes and attachments) whenever image is saved /changed/multiple image(only customisation - no coding) is stored(takes only first image)

WIth force.com we have to customer portal.  I am curious if you can use customer portal and make a mobile version of the pages to display on a mobile device such as an iphone.   This way our site is running all on force.com.   The only other solution is to create another website and use the rest api's.   

Thoughts?