Simple answering machine

Hi,

I'm working on a simple answering machine circuit (just for practice..).
I got it working quite well, counting rings using a 555 counter. The problem is the 555 is a time counter and not ring counter and so even when the call is answered regularly by picking up the phone, the machine still answers the call after the 555 configured period of time. I'm sure there is a better way to do that....
Any ideas?

Please post a schematic.