Like we often talk about, the devs over at XDA Developers are hard at work like they always are. This time XDA member antsm has developed a modification of the Phone.apk that will allow users to record phone calls. This is still very much a work in progress like many things and will only get better with time. He is working on it for the Galaxy S but once it gets working better I'm sure it can be added to many other devices.
* Automatic call recording for incoming/outgoing calls
* Added template system for flexible naming of records. No boring VoiceRecord001.amr anymore
(see /sdcard/.rec_template file for template and more info).
* Disabled stop recording on some actions related to multi-line calling (i.e Hold, Conference mode, etc)
* Disabled stop recording when Dialer minimized to background
Like I mentioned above this is still a work in progress. Things will likely improve and be easier as time goes on. I'd also like to point out that like always when messing with sensitive parts of your phone such as the Phone.apk be sure to do a nandroid backup before changing anything so you can always revert if needed.
[via XDA Developers]