I have a Canon EOS 7D, Speedlite 580EX ll, 2 External battery packs for both, Slik 500HD Tripod,Stroboframe,?

18-55 EFS 3.5-5.6 lens, 35-105 3.5-4.5, and a Canon Powershot S5-IS as a back-up camera. I was aasked by a friend to shoot his wedding. Can you think of anything else that would make the job better? My friend knows I'm not a pro and I'm doing it as a favor for him. (I would like to do it professionally someday as I am pretty good I hear) This will be the 4th wedding I have done as a favor and everyone has been elated. Thanks for your help.