private static final int REQUEST_CODE_EMAIL = 1;
    private TextView email = (TextView) findViewById(R.id.email);

    // ...

    try {
        Intent intent = AccountPicker.newChooseAccountIntent(null, null,
                new String[] { GoogleAuthUtil.GOOGLE_ACCOUNT_TYPE }, false, null, null, null, null);
        startActivityForResult(intent, REQUEST_CODE_EMAIL);
    } catch (ActivityNotFoundException e) {
        // TODO
    }

    // ...

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == REQUEST_CODE_EMAIL && resultCode == RESULT_OK) {
            String accountName = data.getStringExtra(AccountManager.KEY_ACCOUNT_NAME);
            email.setText(accountName);
        }
    }