Journer, it depends on your LEC and state tariffs. My understanding is that a T1 can be delivered anywhere the LEC serves. T3 and SONET I think also can be delivered anywhere.
HOWEVER, you can and probably will be charged what the LEC calls "special construction costs" - that is, they'll provide you the service anywhere you want, but you will pay for all of the costs associated with bringing that service to your location. For DS3 up, this basically means trenching fiber and installing a SONET MUX at your location. Special construction costs in the 5-6 figures are common. If you sign a long-term contract, they may roll some of those costs into your monthly charge. One way or another, you will pay for those costs.
I've never tried to order >T1 to a residence before, it would not surprise me if there are zoning restrictions on what services are offerred, that is, it would not surprise me if they don't have to deliver >=DS3 services to residentially zoned areas, only commercial/industrial. I know I'd write that into the tariff if it were my call. LECs generally don't have the necessary infrastructure anywhere near a residential area. This is why FIOS/PON is such a big deal - telcos generally don't run fiber anywhere near your house; you're darn lucky if they run it to your neighborhood.
As a business, you really want to get your office space in a building that is already served by fiber to the basement. Better yet if there are a few fiber providers in the building, like your LEC and at least one dark-fiber or metro-fiber provider.
Incidentally, if you want big bandwidth, the cheapest way to get it is to be in a provider-neutral data center. Remember that ordering a DS3 circuit from your LEC just gets you a line, not Internet access - that's extra, and not a small bit extra either.
Finally, being an ISP is harder than it looks. Remember all the small ISPs from the bubble? Where are they now? The ones that survived mostly got eaten up by telcos or cable cos, there are very few indepdendent ISPs left. This is not a coincidence. Every time I've helped someone look at the business case for getting into the ISP business, the result has been the same - it's a bad business decision.