An interesting problem, but like all electrical problems a simple bit of logic will soon find the fault.
I tend to agree with everybody above, but the blowing of all the fuese puzzles me a bit as well, as for this to occure you must have a dead short (or a large amount of current being drawn - which may be the case if for example the heated rear window is earthing the stop lights etc)
The first things I would do (and in this order as well)
1) I presume the starter motor is working so the -ve from the battery to the starter motor seems to be intact, so therefore If the earthing is going to be a problem, then its going to be between the engine and the body - there should be a fairly large cable (strap) between the engine/gearbox and one of the main front to back beams / some other large bit of the bodywork. - This is likely to be damaged/broken/missing in your case - either way I would remove it, sand down the metal work under it (to remove any rust etc) and then replace it with a new one if you are in any doubt.
2) Then get a multi meter and check the voltage you are getting between the two terminals on the battery, and then check the voltage between one of the fuse folders (the supply side - trial and error) and an unpainted bit of body work (not the engine).
They should be the same. Then try things again and see it one of the circuits starts to work. If they do put the fuese in one at a time to see if things start to work.
3) if the first fuse blows/ the circuit does not work then i'm afraid your going to need to pick a simple circuit (e.g. stop lights) and go fault finding with your meter.
I always find the stop lights are easy as you can easily make them come on by pulling both cables off the top of the master cylinder and conecting them together, and there are only two bulbs and nothing else slaved (e.g. main beam etc) off them
4) If non of this works let us know how far things get, and what works/does not so far, and ill come up with more of a plan