TI, CSR, Broadcom, etc have tiny chips which provide multiple rf technologies (wifi, gps, bluetooth, fm radio) in one. I don't know prices, but if the total for a prototype was pushed up to $75 it would still be much cheaper than other alternatives and still within range to replace my phone.

Increasing the cost seems detrimental to their primary goal:

"We plan to develop, manufacture and distribute an ultra-low-cost computer, for use in teaching computer programming to children. We expect this computer to have many other applications both in the developed and the developing world.

Our first product is about the size of a credit card, and is designed to plug into a TV or be combined with a touch screen for a low cost tablet. The expected price is $25 for a fully-configured system."

Check out the BeagleBoard or Bug Labs, they do basically those things and cost >$100 each.

Yup. A four-port USB option would be nice, though, to make it just a touch easier (and cheaper) for those who want to pile on the features.

With only two, after you've added a keyboard and mouse, you're already out of expansion options for the desktop pc use-case. (Of course you can add easily a hub, but I just have a feeling that you really shouldn't have to.)

pick up a Logitech Wireless Solar Keyboard and a compatible mouse (like the M305) and they can both use the same USB receiver. plus, it's a solar powered wireless keyboard!

* you'll need to bind the mouse and keyboard to the same receiver on a windows machine before you connect it to your linux box until linux unifying support is available.

There are obviously trivial workarounds to the problem. I was simply making the point that it didn't have to be a problem in the first place.