Hi, I have been searching high and low to find someone else with a graffiti theme. Like you we plan to have a large piece of art that resembles a wall for people to graffiti their messages of advice for marriage. We plan to have this framed and hang it above our bed!! I have found a cake at www.spearmintwedding.com - a graffiti cake that looks romantic as well.
We have taken a photo of graffiti that resembles love in a location that is close to us and have played around a little with it on the computer to personalise it and make it an invitation.
I would love to hear of any of your ideas as want to make our wedding modern and romantic whilst classy. We've soon realised that planning such a unique wedding is probably taking more thought and creativity than the traditional wedding, but know it will be worth it to make it our own! I look forward to hearing from you or anyone else with ideas!!