RIM is in a bit of a Microsoft catch with the legacy distinction between its BlackBerry Enterprise Server (BES) vs. its consumer BIS offerings. (These are the two types of service that connect your BlackBerry to your e-mail.)
In order to provision the very most basic type of sync functionality you have to (a) be part of a corporation with BES installed on its servers (b) deal with managing outsourced BES or (c) deal with multiple add-on applications and various kludgey, fussy setups to get your mail, calendar and contacts to sync between your BlackBerry and your desktop. In either case, you won't have push GMail (which Android, iPhone and Windows Mobile, ironically, do have). BlackBerry has recently tried to fix this but their GMail fix slowed down my BlackBerry Tour to the point of unusability.
BlackBerry's danger is that they are stuck with BES as system that allows command and control security from the corporate IT center and seem loathe to provide effective and competitive solutions on the consumer end and small business end. Sounds a bit like Microsoft.
But there is one area of mission critical business functionality that BlackBerry is as behind the times as the rest of the mobile platforms and that's document sync. With the partial exception of Android, the ability to read and edit documents on a mobile platform and sync them back to your desktop is still only provided by add-ons. A company called SugarSync seems to be filling that gap most effectively. Combined with DataViz Documents to Go, you can get the sort of document sync functionality that BlackBerry should be offering natively. SugarSync doesn't offer document editing and DataViz only offers syncing via desktop cable or with a BES server, with its own software installed as well. But together, they're a great combination. Now I can have a spreadsheet, for example, of my time and activities log on my BlackBerry always in sync with the Excel spreadsheet on my PC. And my novel too can get more work done by being in both places at once. Further, SugarSync has the same backup functionality as offerings like Mozy and Carbonite, but with a far larger offering and full offerings for all the top North American mobile platforms.