When working on a project my scripts often have some boiler-plate code, like adding paths to sys.path and importing my project's modules. It gets tedious to run this boiler-plate code every time I start up the interactive interpreter to quickly check something, so I'm wondering if it's possible to pass a script to the interpreter that it will run before it becomes "interactive".
That can be done using the -i option. Quoting the interpreter help text:

-i     : inspect interactively after running script; forces a prompt even
         if stdin does not appear to be a terminal; also PYTHONINSPECT=x

So the interpreter runs the script, then makes the interactive prompt available after execution.
Example:

$ python -i boilerplate.py
>>> print mymodule.__doc__
I'm a module!
>>>


This can also be done using the environment variable PYTHONSTARTUP. Example:

$ PYTHONSTARTUP=boilerplate.py python
Python 2.7.3 (default, Sep  4 2012, 10:30:34) 
[GCC 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> print mymodule.__doc__
I'm a module!
>>>

I personally prefer the former method since it doesn't show the three lines of information, but either will get the job done.
Is it possible to get the Python Interactive Interpreter to run a script on load?