Modem Spy is handy utility for phone calls recording.
Modem SpyFeatures:
1) records phone conversations.
2) records from microphone.
3) plays back recorded mesages via phone line.
4) Plays back recorded mesages via sound card.
5) Can record ALL incomming phone calls.
6) Has built-in software automatic gain control.
7) Detects and logs Caller ID.
8) Pops up caller ID information.
9) Super Spy mode will hide

Modem Spy behaviour. Nobody will know that you are recording phone calls.

Spy on all of your phone calls!
Automatically tap telephone conversations
Record from microphone like Dictaphone
Voice Activated Recording option available.
Play back recorded messages via telephone line or computer speakers
Record ALL telephone calls automatically
Built-in software automatic gain control
One click Email sendind with attached record.
Detect and log Caller ID
Friendly program interface allows you to make quick notes to remember call contents
Convenient popup Caller ID window
Optional remote party notification before recording. It is required by law in some contries.
There is Super Spy option for stealth recording.
Optional answering machine mode.
Recording from data modem is possible (you will need to physically connect your modem and sound card).
Convert your records to any voice format! (MP3, WAV, etc)
Program size is only 220 KB. Compare that to the footprint of other multi-megabyte software!

Modem Spy is the Shareware version. The full version can be purchased by clicking on the "CLICK HERE TO ORDER" button below for around 34.95USD.