vicidial.org

Would it be possible to build a purly mechanical dialer
Just like an old centraloffice switch before the digital area

vicidial can interface with analog phone lines if you like.

if you are running windows, google "windows dialer"

I also found this: http://www.iansharpe.com/phone-dial.php sorta interesting.

maybe explain your needs a bit more and our community can chime in to help you.