Ouch!!
Yes, my 3.34MB image based on Johan's formula blows out to some 50MB!! and yes "egarayblas", as you would, expect the error code returned was "Out of Memory" . This obviously creates a problem for a map browser as for this app to be truly useful it we will need to load reasonable sized maps with enough detail to make them legible, particularly when zoomed out. Somebody must have come across this before, is there a solution short of going out and buying the biggest, meanest PDA around (not an option for most of us).