desktop pen

i need a small software that draws free lines in the desktop. those lines must be draw above some programs that are running, so the window must be transparent. the software that is running in the desktop and where i want to make the line can not be froze while i am drawing the lines. the drawing program is very simple -just draw free line, and erase them. each line must be set as a layer so when i erase i erase a layer. the drawing software must be drawing line in a multi monitor desktop (more than 4 monitors). extra will be given for fast development. ## Deliverables the drawing software must only have a small pop up menu where i choose the widht drawn line and the color of the line , the pen or the eraser, layer if visible or not(the layer comes in a list menu , that if checked is visible if not is invisible and quit the application. when i choose the pen it should open a small pop up option where i chosse a new layer or still keep the same layer or a previous layer (in a list menu a choose the layer number). every time a choose a new layer it should icrement the layer number(1,2,3,4...) every time a choose a new layer the software must save all the layer and lines in a temp folder in case i want to reopen it , just go to the folder and open the file and appears all the lines that i draw in that session. every time i quit the program the information is erase from the temp folder. so when i open the drawing software it opens a new "file". ## Platform xp service pk2 and multi monitor