Are you a .Mac subscriber who's been using the built-in bookmark syncing app? Come Sunday that service will no longer exist as part of the MobileMe transition, so if you want to do one last sync you've got to get it done this weekend.
Shortly after the MobileMe announcement last month Apple sent out an e-mail to current .Mac subscribers detailing this change. Friday, the company extended the transfer deadline to July 6, along with providing a how-to guide to make sure you've got everything synced up one last time. You can get full instructions on how to do the sync here.
The July 6 deadline, which is Sunday, leads me to believe that the MobileMe changeover may be dropping a day or two early from the expected July 11 release date.