A performance chip is probably the quickest and easiest thing to try. I have a 2002 Ford F250 with the 5.4 and have considered trying one. Here's some info. If you get one, let me know how it works. Just too much money for me right now! BTW, a K&N filter will help also.
http://www.thepartsbin.com/guides/ford/f150/performance_chip.html