You can't cheat Amdahl's law anymore than you can give birth in one month with nine women. The law is a rather simple idea similar to chemical kinetics, when you think about it. i.e. a rate limiting steps.
If you are interested in a non-mathematical description of Amdahl's law have a look at http://www.clustermonkey.net/Parallel-Programming/parallel-computing-101-the-lawnmower-law.html