One of our contractor uses this for phone. It routes all calls to their targets depending on how they are signed in.
http://fonality.com/trixbox/
and then remote web workplace for the computer.
http://en.wikipedia.org/wiki/Microso..._Web_Workplace
It is essentially like the person is working right in the office other than face to face meetings.
You could also use any VPN firewall from Cisco (or another brand), a terminal server, or just remote desktop into a dedicated machine.