Considering the number of Government services provided, you'll want to start small and prioritize the most requested services to integrate into a MyGov. Initially, being able to get people to the services they need (even if you haven't integrated technologically) would be extremely helpful. Some services that you could initially add, or integrate, would be:
* Postal Service change of address (saw this in another idea...great one!)
* DMV processes (common ones like license renewal, registration, etc)
* IRS tax information (current status, is my tax information under review for a possible audit, registering as a business, etc)
* Social Security (SSN cards, benefits info, etc)
* Health Services (health records, insurance help, referrals, etc)
* Education (loans document, request for loans, etc)
This list, I'm sure, can go on and on. But at least centralizing the access to that information would be a critical first step. Then look at the integration of those services.