Drawar

Keep 1 web site, just have two different sections. It'll be easier for your customers to remember and easier to manage. :)

One website with information for each office. This is just one way to do it: http://guttmacher.org/about/contact.html

Why would you make things more complicated for your customers?

Certainly have information for both office where it's relevant, but aside from that it sounds silly. One website.

One website. Your home page should be relevant to both locations, with more specific detail on pages about each location.

Only consider crowbar separation if you're offering different things in each place.

For things like contact info, show both on the same page, clearly labelled.

For office-unique lists or more detail, consider something like a tabbed page or a branch-point where the user selects which office they want to see.

But I would never keep them on two different sites...

I would have one website serving as a portal. Say, from the splash page you could either choose to go to ny.html or tx.html or something of that nature, so that each page could cater to the customers from each respective state.