With a rooted phone and an app you can overclock or underclock your processor. Also, off Android, with some hacks you can boost power of a wifi router and wifi antenna. It seems to me that if you can do those things you could boost the reception of your cell antenna some how. Am I right? If so, how?
As a telecom engineer student, I know that one of the main limitation for power is the EIRP (http://en.wikipedia.org/wiki/Equivalent_isotropically_radiated_power).
Overpassing the EIRP is one of the must known way to increase wifi router power (by adding a better antenna, which leads to an increase in gain, and in power RX/TX). This power is perhaps fixed by the software in Android handsets, and you could use this parameter to leverage the emission power.
But, as far as I know it's illegal (at least in France).