After finally figuring out how to compile the source code under windows (which took a while with significant help from all the people on the #powder IRC channel) I finally managed to do what I'd been trying to do earlier with Cheat Engine by removing assembly lines.
Except this way it actually runs on Windows 7. :O
Each corner of the screenshot is one of the different mod files I put in this zip. The zip also includes a DLL file that needs to be in the Powder Toy directory in order for any of these to run. It'll ask for it if you forget.
I made it in an incredible rush while at a library. In the one without air update the whole Air_update thingy is commented out. The other three are the same three commands used for setting x and y of velocity and value of pressure on every frame. @_@
When I get a chance to do it again I'll properly compile it instead of saving the debug .exe (a mistake on my part), and save a whole copy of the source for each version.