Google added three new features to Google sites and Google site features will be very useful for premium customers. Google added start page, private gadgets and end-to-end security features in Google site.
Start Page: Google site viewers can now customize and personalize Google sites pages that they visit. Google site pages created with start Page template allow individuals to add and organize their own gadgets to customize the page. The site owner chooses "Start Page" in the page type menu, and then adds content that they want everyone to see to the top of the page. Each viewer can then customize the page to see their own personal gadgets.
Private Gadgets: Before this all Google Gadgets are public so if you know the URL can view the source code. Now domain administrators can upload gadgets to Google Apps, and only members of their domain will be able to see and add these gadgets to their Sites. You can find these gadgets in a directory with your company’s domain name in the gadgets directory.
End-to-End Security: Google sites added some more security features match the security of Google site. For example if Google sites is encrypted then the Google Gadget will also be encrypted.
Source: Go go gadgets…in Google Sites