My real interest was to explore how I might improve upon the on-device applications from a productivity perspective. What I found was that the onboard apps leave much to be desired - especially tasks and memo (reference).
I use eProductivity for Lotus Notes, along with several reference databases. The first reference database is mapped as my personal Journal, so it syncs automatically with the BlackBerry. The BlackBerry only provides native support for one "MemoPad" database on the device. I'd like to get my other reference databases to Sync with the BlackBerry as well. When I used to do integration with the Palm, I used products by Sybase and CommonTime with great success. I know that there are many equivalent options for the BlackBerry. Ideally, I'm looking for something that if I recommend it to a client they won't balk at price or complexity to deploy.
Are you synching additional discussion/document/reference databases with your BlackBerry? If so, which sync tool are you using and how is that working for you?