Is there a way to automatically update application on Android?

i had the same issue, now i check at the start of my app if theres a new version in my configuration xml.

I compare the actual version with the tag "< app_version >1.1< /app_version >" of my configuration.xml if its lower i ask with a custom AlertDialog if the user proceed with the upgrade

Intent intent = new Intent(Intent.ACTION_VIEW ,Uri.parse(myapk_link));
startActivity(intent);    

after the download the user has to run the package manually.

if you choose the update from the Android market use:

Intent intent = new Intent(Intent.ACTION_VIEW ,Uri.parse("market://details?id=com.package.name"));
startActivity(intent);  

com.package.name must be the "package" of your app

or

Intent intent = new Intent(Intent.ACTION_VIEW ,Uri.parse("market://search?q=" + APP_NAME));
startActivity(intent);