When Flying Meat first started getting successful (ie, people really started noticing my work), I was asked a lot where I found the time to code. After all, I was working a full time day job and I played guitar and rock climbed as much as I could. The answer was easy and obvious- I didn't own a television.
I think people really underestimate the amount of tv they fill their lives with. Just turn it off, and unplug your cable. Really, you can do it. That Thursday show you "need" to watch? You'll get over it, trust me. And if you really really really need to watch it- buy it off the net and put it on your iPod to watch when you've got some downtime somewhere.
These days I do own a television, but it's not hooked up to anything but an xbox, a wii, and a mac "media server". So it is only ever used for playing games or watching the odd movie. There's so much more to do with my time than doing nothing.