Here's a quick way with particles ...

... create a plane, select Particles->Emit from object->option box, choose Surface emitter type (I'd sugest tubes for particle type ...);
add a gravity field to the particles and you have the basic setup ...
... now you can put a second plane to act as the ground, set some collision events (select the particles and the plane->Make Collide), use mel for randomness (like drop size, speed ... etc) ...
... but this is just the beginning, if you need more details I'm glad to help.