You might be interested in the "digitalwritefast" header: Google Code Archive - Long-term storage for Google Code Project Hosting.
It can change your pinMode(), digitalRead() and digitalWrite() calls into direct port manipulation whenever the pin number is a compile-time constant. Just include the header and change the pinMode(), digitalRead() and digitalWrite() calls to pinModeFast(), digitalReadFast() and digitalWriteFast(). This will make your code just as fast and more readable.