analog hookup through digital line

[Eugene Fiume <elf@dgp.toronto.edu>]

I'm doing some work at a place that only has digital phone lines
available to offices.  Is there a creative piece of magic that would 
allow me to connect my laptop to the phone line through, say, the 
headset of the telephone receiver?  I know I can't connect the straight
digital wire to my laptop, but the connector to the headset does snap
into my RJ11 input.  Unfortunately MWAVE doesn't "hear" a dial tone.
I don't mind doing all the dialing manually, etc., but I really would
like some telephony capability.  Any ideas?

Regards,
Eugene Fiume