which is a minimalistic python wsgi development server with support for code reload?
I'd recommend paste or CherryPy.  They're the easiest to get up and running with.
From what I can tell

wsgiref - no code reload
CherryPy - more than just the server
mod_wsgi - all the apache overhead
paste.httpserver - paste is a huge package with other stuff in it
flup - same as paste, too much stuff.
Spawning - never used it but seems lightweight enough.
Tornado - not really wsgi + full "framework" 
Werkzeug - runcommand

any others out there? which one you prefer?