{{{
#!python
class PsycoMiddleware(object):
    """
    This middleware enables the psyco extension module which can massively
    speed up the execution of any Python code.
    """
    def process_request(self, request):
        try:
            import psyco
            psyco.profile()
        except ImportError:
            pass
        return None
}}}

Note that this should only be used on 32bit systems. See http://www.alrond.com/en/2007/jan/25/performance-test-of-6-leading-frameworks .

One possible way to determine this automatically:
{{{
#!python
from platform import architecture

if architecture()[0] != '32bit':
    raise Exception("Don't use this on non-32-bit platforms")

class PsycoMiddleware(object):
    """
    This middleware enables the psyco extension module which can massively
    speed up the execution of any Python code.
    """
    def process_request(self, request):
        try:
            import psyco
            psyco.profile()
        except ImportError:
            pass
        return None
}}}

----

One more issue I have with this -- why is import done on every request as opposed to module load time? The following looks saner to me:
{{{
#!python
from platform import architecture

if architecture()[0] != '32bit':
    raise Exception("Don't use this on non-32-bit platforms")

# let ImportError propagate at module load time so that people can notice and fix it
import psyco

class PsycoMiddleware(object):
    """
    This middleware enables the psyco extension module which can massively
    speed up the execution of any Python code.
    """
    def process_request(self, request):
        psyco.profile()
        return None
}}}