For those wondering: The rule thumb here is that light travels at one foot per nanosecond. 300 ns =0,3 μsec. Electricity is a bit slower but the same order of magnitude.
To put things into proper units: speed of light in vacuum is approx 1.8 terafurlongs per fortnight, and electricity in wires has a pace of similar magnitude, and sound in normal atmospheric conditions shuffles along at approx 2.1 megafurlongs per fortnight.
Well, but its also just wrong. Its 12.5% to low. Thats why "about one foot" sounded absolutely wrong to me.