I posted about how much 'unuseable' fuel was in the tanks of out R65's, and I got about .5 gallons out after draining the tank with the fuel tap in the reserve position.
So if you can remember this little tidbit of in formation, when you run out of fuel, get the front wheel up, like on a curb, let the fuel run the the back of the tank, then tip the bike to the left, to get the fuel over to the left side.
Might just give you enough fuel to get you out of your 'situation'.
Also you could try cutting the pipe for the reserve postion in the tank, but I would add an inline filter, as you are taking fuel off of the bottom of the tank then.