I just began using a new service that I wasn't previously aware of, so I thought I'd put up a post, in case anyone is doing closed captioning. If this is old news, please forgive me....
So we just started using a service to do the CC via FTP. After we create a program in FCP, we export a .wmv file (via 3rd party software) and send it to the captioning house. They do the captioning and send us back a .mov alpha channel file that drops onto the timeline and bam! Captions. The initial set-up takes a while, they basically need to find out what line of video to place the captions on for your particular system/capture card. Anyway, it made me happy. The place we're using is abercap.com.