Arevos

Systems like mod_python and CherryPy probably use file timestamps to check if the source has been changed. I know that whenever I change my CherryPy source, the CherryPy server automatically reloads itself. Presumably, mod_python does something similar.
Possibly. I know it retains the PHP interpretor in memory. Perhaps some further caching takes place for executed scripts. I'm not sure whether PHP has anything equivalent to Python's bytecode.
Yes. CGI send data to a program through STDIN, and takes the output from STDOUT to send in a HTTP response. The CGI data passed in through STDIN has to be parsed, and that's what CGI libraries do. CGICC is a CGI library for C++.

Still, just because you can do something, doesn't mean you should. There's a reason few web applications are programmed in C++

Arevos

mod_python always struck me as too complex. CherryPy is nice, though.

You might also want to take a look at libraries designed to optimise CGI scripts, such as FastCGI.

DaveQB

The problem though, with using mod_python , CherryPy, Django etc is the serve needs to support it. The problem I find it most commercial web hosts have PHP enabled, but not the above mentioned frameworks.

How do people here get around this ?

Sure, I can run it on my home server, but the bandwidth wont be near the same and would slow down my families how net browsing.

Arevos

Get a Python host, or a dedicated/virtual host. There are a few around, but they are always more expensive than a straight PHP option. In terms of low cost, PHP has the edge over most other languages.