an officemate had MenuetOS (so small, you can have two copies of the installers on a diskette) running on an old lab PC. impressive eye candy, really. but leave it to neil to debunk it, and giving the option to run ReactOS instead. at 4 megs, and a GUI that appears to be a hybrid of a Win2000 server OS and a Linux box.
however, there are still two reasons why the option to revive the old pc is less-than-desirable: an old, seldom-cooperative monitor, and the prospect of not having dialup connectivity on the setup.