Using Ajour to Dial and Phone People
To see the full range of possibilties open the help file and search for "dialing".
You can have individual numbers dialed like "1 2 3";
this can often be useful when required by e.g. answering machines.
Notice that the dial function will only work with a voice-modem and not with a DSL based solution.
This is because DSL uses a different frequency (over 4Khz) than "voice" (what phones and fax-machines use).
However, you can have both DSL-modem and a voice-modem connected to your computer at the same time.
Such solutions are often called something that contains one or more of following phrases:
"catch-a-call", "1-in-line", "DSL filter / splitter" etc.
Collection of links that provide further information: