Use of Voice Over IP, thru Cloud Services, will result in tremendous savings.
Example: Google-Enterprise, now available at NOAA, allows 'free phone calls' from desktop-to-land/cell phones.
1/ That will save the government upwards of 10 cents per minute.
2/ Email within that same service, will also result in TREMENDOUS cost savings as well; reduces costs in hardware, man-hours, and trouble-shooting.
Google-App is DOD-certified, I believe.