Oh lulz Ping. Me and five of my buddies painted a giant mural on the walls of our school as well. Took a long time, but it was very worthwhile. I hope your mural is fun to paint and turns out as great as your concept sketch. :D
I've completed the mural and I'm getting a photographer to take pictures of it today. I'll be able to get onto commissions from monday evening onwards (Monday's my last day of exams) ;D