The SurfShelf does what many home-made and Ikea-bought shelves, tables and stands do: put your laptop in front of your face while you're walking on a treadmill. And it works beautifully.
The Price: $40
The Verdict: This is one of my favorite inventions ever. Treadmill computing—or using a treadputer—is one of those ideas that's ideal for out-of-shape people who work at home, since you're still capable of doing all the work you were doing before, except now your legs are moving. Its major barrier is the fact that you had to have a treadmill, plus a stable enough platform to keep your laptop on. If you could rig that up yourself, great, but most of us were too lazy or too disinclined to. Now it just costs $40.
To answer your first question, yes, it is ill-advised to type and run at the same time. But typing and walking fast, or running and just watching something on your computer works just fine. In fact, I'm typing this entire review up while I'm walking on my treadmill.
How it works: The SurfShelf consists of two interlocking polycarbonate pieces supported by either one or two straps to your treadmill, elliptical or stationary bike. If rigged up correctly—something I had to ask for help with—it's incredibly stable, capable of supporting somewhere in the neighborhood of 55 pounds. Plenty solid enough for your laptop provided you don't constantly lean on it.
This thing has basically turned working into exercise. By spending 2-3 hours a day typing, emailing, and reviewing while walking, you basically get free calorie burn doing something you'd be doing anyway! According to Nike+, 2 hours of fast walking while working burns 1,000 calories. And even if you're not lucky enough to work from home, being able to watch YouTube or BitTorrented content makes any workout go faster.
Assuming you already own a treadmill that's gathering dust, the SurfShelf is the easiest way of getting you back on that thing. And if you're a freelancer or the type of person who spends much of your day on a computer, this could be the healthiest gadget you buy this year. [SurfShelf]
Makes treadputering an incredibly straightforward process
Stable enough that you can trust your laptop to it
Instructions aren't universal enough for every type of exercise machine, but you can get the idea fairly easily