How I get through (boring) cardio

Long story short, I read.
Long story long, it's all about flow.

See the book I've been reading the last few elliptical sessions (did 45min today, Woop) is all about human emotions. How they work, what they're for, how to use them, all that good stuff. Very very insightful and interesting book, well worth a look for just about everyone.
So, as I'm striding along on the elliptical today, book in hands, I was reading about a chapter on empathy, related to which is something called 'flow'. Flow, as far as I understand, is when you get so into an activity that you lose yourself. It's like a transcendental state of hyper concentration, yet simultaneous oblivion.
We've all had at least one experience of being so wrapped up in what we're doing that it feels like we're not even giving orders anymore, our body is just performing on autopilot, and nothing outside of that even registers.
The author says sex, *good sex*, is an example of this. (Good sex sans wandering, interruptive, toddlers me thinks)

And I realised, I get this feeling of flow sometimes when I'm reading. Which is why I can go on the elliptical for an extended period of time without even realising how hard I'm working.
I'm no good at running, I feel every little pain and discomfort, and I get bored, even with music on. The time just drags. Lion King can. He talks (and writes) about getting this flow while running.
We're very different.
But reading, on the elliptical, the time passes without me even noticing. It's fantastic!
It's like I just settle in to read this interesting book, and suddenly this machine is beeping at me saying I've burned all these calories and I'm dripping in sweat and my legs feel like jelly.

So if, like me, cardio doesn't really engage your interest, find something else to do (while you exercise) that does!
Apparently just by concentrating and focusing you can get flow, and this exercise without remembering you're exercising.

...But, there's a catch. The task has to be the right level of difficult. If it's too easy, you'll be too bored to reach flow, but if its too hard you'll be too frustrated.
So don't go for calculus, but possibly not a picture book either.
Books about emotional intelligence work perfectly.

Or, you know, if you hate reading as much as you hate cardio, just find something else :)
What else is good to do while exercising? Music? Audio books? Podcasts? Watching TV? Knitting?
Lets share ideas :)