Count me in as one of those curmudgeons who would like cell phones banned from public places. If it's that important, use a pager. However, that's just my personal preference.
As to the law, if I recall correctly the law bans broadcast jamming only. As I understand it, you can implace a "passive" jammer in a building without falling afoul of the law.
As to those who would sue, where is it written that you have a right to inflict your cell phone on me in my building?