A macroscript which produces a space-saving floater that allows you to start/stop/reset the radiosity solution - and change the meshing size. Has a progress bar to show you how far the solution has got - but it doesn't always seem to update on heavy scenes.
Standard Maxsripts (.ms) can be run from the Maxscript button in the utilities panel. To have them always available - save the scripts into your scripts/startup directory.
Macroscripts (.mcr) can be placed in either scripts/startup or UI/Macroscripts - and are then accessed through the 'Customise User Interface' menu in 3dsmax. You can then assign the script to a keystroke - or a button. All macroscripts will appear under the 'Dusk' category in the dropdown.