Pymol script: loadBfacts.py

From the description on Pymolwiki:

Quick and simple script to replace B-factor values in a PDB structure.

New B-factors are provided in an external .txt file, one per line.

By default, the script will also redraw the selected molecule as cartoon putty and colour by B-factor

Full description, examples and usage notes:
http://www.pymolwiki.org/index.php/Load_new_B-factors