http://fusor.net/newbie/
The "Farnsworth Fusor" actually has some fairly basic limitations - it would burn itself out before reaching practical fusion levels, but the Bussard p-B11 approach (later in another article), looks interesting.
http://torsatron.tripod.com/fusor/fusor.html
Direct collection of high voltage electricity.
Certainly, in it's time, Farnsworth's design showed considerable promise, but was sidelined by the push toward fission.