Germany's POST offers postal, shipping and banking services that people there love. I'd much rather deposit my money in a Postal bank that wouldn't speculate with my cash like private banks do, nor operate in their own best interest over their customers. The Postal Service could also be the face of Government backed mortgages and free us from the speculation that destroyed the industry.
Mind you, private finance would hate this idea and lobby against it but these basic services that everyone needs, even the poor, don't have to be offered only through max-profit corporations.
Create a National Bank and Mortgage Company as part of the US Postal Service and bring new life and trust to both concerns.