LaTeX has a library for drawing electrical circuits - used by academics.
I have used xfig to make a set of standard circuit elements - and thus draw circuits.
However: FC4 comes with a nifty diagram drawer called "Dia" which includes electric circuit elements as well as a great range of other options. (main > office > dia) Probably available in FC3 too. If you don't see it (I dunno - yum install dia?) see the project page: http://www.gnome.org/projects/dia/