I use MySQL and also sqlite. However, I also use Spring Python (http:// springpython.python-hosting.com) to use both its DatabaseTemplate utility class and also the remoting functionality. This way, I can have the database code sitting on the server, and then export the data access functions remotely to clients. It is also relatively easy to swap out database engines.
For the record: Spring Python is my pet project. I use it myself, and recommend it to others as well. -- http://mail.python.org/mailman/listinfo/python-list
