I know of three very good books on the actual (or sometimes hypothetical) application of economic ideas to real world problems:
1. Alex Tabarrok's Entrepreneurial Economics: Bright Ideas from the Dismal Science.
2. Some other book I haven't read and can no longer remember.Only three? And one of them not memorable? That's almost depressing...
There is now a third:
3. Better Living Through Economics, edited by John J. Siegfried. It covers emissions trading, the EITC, trade liberalization, welfare reform, the spectrum auction, airline deregulation, antitrust, the volunteer military, and Alvin Roth algorithms for deferred acceptance. The contributions are uniformly excellent and written by top economists.