There are couple of coding examples provided in the Mobile Web Server Book available in http://mymobilesite.net/files/Mobile...er_Book_en.pdf . In the case you find those examples little bit too complicated for your taste (like me) you might try the following as a starting point.

Create a file called hello.psp that looks like this:

text = 'world'
Hello <%= text %>!
Create other file called ht.acl:

Allow from all
AddHandler mod_python .psp .psp_
PythonHandler mod_python.psp
PythonDebug On
Copy those to folder psp under your htdocs. Access with address [yoursite].mymobilesite.net/psp/hello.psp and it should do the trick.

There's not much real action and no access control either, but the purpose is to show that templating is not the only way to do psp.