I have once again been rapturously swept up with the odors and essences of school, so posting has been a little sparse. Until I have some free time to finalize some drafts I’ve had sitting around for ages, check out this excellent article on screws courtesy of Arcticpenguin at Instructables (pdf). Apparently, the reason that Phillips heads suck so much is because they were designed for applications where maximum torque was an issue, so the heads and drivers were designed so that the driver would cam out once the correct torque had been reached. Of course, nowadays cheap Phillips heads are used in applications where the maximum torque allowed by the design of the screw head is much less than the torque needed to get the things screwed in.
Also, Robertson screws were invented by a Canadian!