SmokeThis
Makes a superspray - or pcloud with a material that simulates smoke. This is a quick way to create some smoke for your scene - go into the material afterwards to tweak its color - density - etc manually.
For a max 5 - 4.2 version of this script - please download bspack_r4_r5_v031.zip. Use the original bspack_r42.zip if you want only max 4.2 compatibility.
The only major differences between script packages are slight version compatibility issues - there are no new scripts added between the 3 packages.