While iSync is nice for the basics, I've found that missingsync has worked best for my blackberry and nokia syncing.
http://www.markspace.com/products/symbian/ms-overview-mac.php
There are pros and cons to both models (the iTunes syncing appears to still have glitches with the E71 -- maybe that's user error here). As a phone, the Blackberries are frustratingly not 'smart' for smartphones for many features. RIM seems enamoured with far too many drilldown menus rather than being able to set preferences once. Nokia's voice recognition sw is not nearly as good. But for syncing, overall both platforms are very well supported by the Mark/Space people. Just be sure to professionally keep on them (mark/space) so they will resolve any lingering bugs. Contact, calendar, photo, tasks, files (aside from mp3 or aac), and video all sync pretty darn well.