Why do I feel like I've woken in 1995. This is the second thread I have seen insisting that mosfets must be driven to 10V. Anyway, TIs new Nexfet has 2 milliohm RDS ON at 3V. You can buy fets all day long that are characterized at 1.8V. I have a Core 2 Duo, its core voltage is 1.3V that means it has 500 million fets flipping on and off 3 billion times a second at 1.3v. It is mostly true though, that once you start pushing 100V devices you need a strong gate voltage. Although, if you want to pay a few bucks more you can get some of those gallium arsenide fets rated for 200V and they work at 3V - at a ridiculous 1.9Qg total charge at that.