Something's Hiding in Here has a new installation project in Philadelphia that we can all participate in. Your Message Here is "inspired by industrial letter signs, multi colored text, and everyday sayings... we made our own marquee sign out of wood. now the fun part begins, we want to collect your messages to post on the sign. we're not looking for insightful proverbs, but rather ordinary, simple sentiments."
You can leave your message on their project website and they will photograph the chosen messages and post them on the site on a daily basis.