How can you record cell phone calls?
Which model call phone are you using? If you are a Windows Mobile user, then it will become an easy job. The software ----wm sound recorder can help you to record calls and sms. Then you can record your calls easily.
Maybe you can have a look at :[link removed] Hope help~
There is hardware you can get for this purpose, but if you are looking to to do it without purchasing a device, you can hold the mic from your computer up to the earpiece and record onto your computer.