RightFax solves all of these problems. My company has a co-location in a Verizon data center where we have a PRI brought directly to the server. Unlimited 1-800 numbers, super cheap long distance (almost non-existent), and integration with our Exchange environment equals an increase in fax volume over the former traditional fax setup. With over 500 employees across two states, this solution paid for itself in less than 12 months and continues to save us tons of money for stupid faxes.