The Thomas Knight one actually looked somewhat promising. It had three starter motors connected to an Eaton M45 blower.
I wouldn't touch the one in the link. It looks like a pretty version of the bilge pump models. Also, the power required to actually drive an electric supercharger is freakin' insane. They don't mention jack about current draw.
**EDIT**
ROTFLMAO!!!! I just read the detailed specs. It draws 2.2 amps. My blower motor in my dash probably moves more air.
What a joke.
BTW, somebody should have said that they put one of these on their car for an April Fool's day joke.
**EDIT**
BP