A friend wrote to ask me the following question:
You mentioned Tivo which is one of the best media recording solutions on the market. Of course, it is far from a free solution! If you don't mind investing in a bit of hardware (and you already have a desktop or laptop PC), you can find a device that you hook into your cable box to record shows. These devices are called TV tuners, and they come in two broad categories: external devices that plug into your computer via USB and internal devices that you have to install in a PC (similar to an internal video card). I've used internal TV tuners in the past, and they are great if you don't mind opening up a computer and doing a little bit of geekery. However, most people prefer external TV tuners because they are pretty much plug-and-play.
Lifehacker did an article earlier this year about external TV tuners, and I think it's a great write-up. I would recommend the WinTV HVR 2250 from Hauppauge because I've heard great things about the company, it supports dual tuners (you can record one show while watching another), and I like the remote control that comes with it.
I hope that helps!
Image courtesy Hauppauge