It's pretty late notice, but there is the 1,000-person ukulele event going at the Yokohama Hawaii Festival tomorrow opening at 1PM. You can download the PDF for Hawai'i Aloha, the song to be played, here. This link will take you to the musicians from Hawaii that are playing there this weekend. For those that are interested, there are also some hula events.
Unfortunately, I am scheduled to be at a different ukulele event this Sunday.