Every summer I explore town and do a similar scavenger hunt.
I've found that of the 10 payphones put up on city property throughout the main part of the city, there are two left. One is in front of the city bus station, and the other is in a really crappy old section of our downtown between a pawn shop and a "travel agency" (quotes used because I'm almost positive it's a front).
Only a few gas stations in town keep their payphones inside the location. Many have drive-ups, but they're almost always COCOTS and either in non-working condition or just outrageously expensive.
There are two older working Ameritech phones in the Open Pantry (kind of like a Safeway with a Mobil gas station attatched), a few in an old laundrymat, a couple in our strip mall, one in the high school (but I don't know if it works), NONE on campus, and a couple at various restaurants. There were also a few at our regional airport (which is the only reason I've EVER gone there)
I didn't get to finish my search this summer, but my final total of non-COCOT phones totalled 12, and my search of COCOT phones stopped at 15 before I got sick of biking everywhere.
For reference, I'm in Oshkosh, WI with a population of about 67,000 + about 10,000 additional people on campus and about 10,000 in outlying townships and villages.
