We have looked at these for various applications (initially to use in conjunction with our own software to allow easy Chinese text input). Not sure if any allow direct input now to a BlackBerry (I think probably not) but like above way to much hassle as they are. Easier to just use the keyboard on the BlackBerry (or buy one of our keyboards for your BlackBerry ;) ).

They where fairly accurate though and I must admit I still use one on occasion when in meetings or at conferences where I always hand write notes anyway (I use the electronic form as a backup in case my notebook goes missing).