The first was a pointer to Scienceblog article on the work of Roughgarden and Tardos on selfish routing. Here is their main example: Consider two roads from city A to city B. The first road takes an hour and the second road takes p hours, where p is the fraction of people who take the second road. The best way to route to minimize total travel time is for half the people to take the second road (average time = 3/4 hour). If everyone acts selfishly, the only equilibrium is everyone taking the second road for an average time of one hour. For more details see Tim Roughgarden's home page.
The other article pointed to Microsoft's research Penny Black Project which hopes to prevent spam by making sending email "expensive." The variation using complexity requires the sender to solve a moderately hard problem generated by the intended recipient.
Always keep in mind that what happens at Microsoft research, especially amongst the theoreticians, should not be read to imply any future email policy at Microsoft, no more than one can determine future NEC policies from my own research.