Cell carriers used scheduled access to the wireless channel, which provides guarantees on bandwidth and latency so that your speech is understandable. 802.11 provides random access, which is great for bursty Web traffic but terrible for voice when multiple people use it simultaneously (and undoubtedly you would not be the only one using VOIP over your WiMax AP).

For example, an 802.11b network can handle ~140 simultaneous Skype calls in theory, but only about 6 in practice. For a more detailed analysis, see this paper

A satellite can't observe a solar flare from space and warn us 15 minutes before it arrives at earth... any warning that the satellite sends to earth would arrive at the same time (or later) as the radiation it detected.

So, the satellite must be able to detect the solar flare well before it happens, but anything the satellite sees 15 minutes before the flare, we also see on earth 15 minutes before the flare. Maybe the satellite has a clearer view of the sun, but that just means it is a better warning system than instruments on earth, not really an early warning system.

>> -light, -safe, -cheap: Pick any two.

This is not really true: the aptera provides all three. The egg-shaped cab is extremely safe and light, the list price is around $20K, and it supposed to get 300mpg. It is also high off the ground to be a good height relative to the bumper of a high SUV or truck.