General developer forum

I think we can solve the last problem i.e. the simultaneous editing of a single pixel by synchronized methods (the monitor mechanism) that would allow only one thread to send editing instructions over the HTTP at a time.
And i also remember doing some calculations around my 3rd semester maybe (actually me and my friend did it on the go while discussing something else) that gave the probability of such an event to be very minimal (which of course would rise as we try to make more people edit simultaneously). I can't recall all that as of now (already into end sem exams ) but it takes a lot of things into consideration like data transfer rates of clients, processor speeds etc. (I suppose I'm going on the right track, do comment if otherwise).
And I think I can implement the proposed solution for sending parts that were edited rather than the entire image, that would simply require me to maintain a temp array of pixels(edited) apart from the main array and temp is sent and plotted over the main array at the client side.
And if I make the transfers at every mouse release (supposing user draws a line dragging mouse pointer with a key pressed), using synchronized methods, I think it will be workable for atleast a few users if not a very large group.
I'd like further suggestions, thankyou very much.