Great Idea, but . . .
. . . we don't need to restrict it to tony restaurants.
It's considered poor taste to use a cell phone in a nice restaurant, so more of them are creating rooms and other access points. Link.
Let's hope the trend spreads to other public spaces, as well. Who knows, maybe some day we'll have "cell phone" and "no cell phone" seating. I'd opt for the latter every time.
For whatever reason, I find public cell phone use annoying. I've always found loud talkers--those folks who want everyone to hear what they're saying--annoying. The cellphone has increased the loud talker syndrome 10-fold.
Aside: The Nextel two-way phones are ratcheting up the annoyance an additional level. With those contraptions, we get to hear (i) the person in our presence, (ii) the person in Nantucket, and (iii) the double beep. Nothing to lose sleep over, but annoying.