Just as a data point- I've driven with the read out on 0-miles for maybe an extra 20 miles before hitting a gas station. Can't say how much fuel was left in there at the 0-mile mark, but it's at least 2-gallons or more. I think Toyota made the read out pretty conservative.
That being the case, like
@
ElectroBoy
said about tank sludge, probably not the best to push it to the bottom of the tank on a regular basis. Although gas is pretty clean these days and I personally haven't heard of anyone sucking sludge in the last 10 years or so. YMMV of course.