If you use GMail Tasks and are a BlackBerry user, there is a new application currently in beta, GMTaskSync from BlueBerryNite Workshop, that you’ll want to check out. GMTaskSync allows you to bidirectionally synchronize your GMail tasks with with your BlackBerry.
GMTaskSync is currently free while in beta through March, although it appears that BlueBerryNite Workshop plans to charge for the application once the beta ends.
Download GMTaskSync for BlackBerry from the RIMarkable App Store...