I downloaded Hamachi today. What is hamachi? A very simple, secure way to connect a group of PCs together in a shared, private network. Its very slick, has good installation help and works just as expected.
Now we can all connect together and also connect with our (small number) of PCs and servers that live in the office.
You create a network, members join the network by entering a password and once they are on the network you have as access to their machine in an identical fashion to a machine on the same subnet. You can also access a web-server if they happen to have one running.