It's in the Captions
From: Speech Technology - 04/2008 - page 12

Sprint Nextel introduced a new service to its Relay suite of consumer
accessibility products. WebCapTel, a free Web-based service, allows deaf or
hard-of-hearing users to read transcripts of their calls. Users may still
speak to another party, but that party's spoken statements appear as text on
the user's screen. 

Links:
WebCapTel
http://www.sprintrelay.com/webcaptel.htm
http://www.captionedtelephone.com/webcaptel.phtml
http://www.relaysouthcarolina.com/captel_webcaptel.htm

WebCaptel FAQ
https://www.sprintcaptel.com/faq.asp?ret=wct&ani=&sid=&tab=5