From: DeskNow Knowledge Base
http://www.desknow.com/kb/

How to sync with BlackBerry Devices
http://www.desknow.com/kb/idx/17/138/article/

You can sync your BlackBerry device with DeskNow using a SyncML client for BlackBerry, such as those available from http://www.nexthaus.com .

Important. Before starting, login into DeskNow with your web browser, and go to Preferences/SyncML. Here you can select which contact folders / calendars to sync with. By default, no folders/calendars are selected. 

Please consult the connectors' manual for initial installation and setup.

The following parameters should be used to connect to DeskNow:

Server URL: http://www.server.com/desknow/sync

Folder name for contacts: ./contacts

Folder name for events: ./events

Folder name for tasks: ./tasks

For any troubleshooting, refer to the connector's manual (some specific settings may be needed for internet connections, depending on your carrier). Check the log.SyncML and log.SyncMLProtocol log files in DeskNow to see if there are any eror messages (if nothing appears in the logs, it means that the device is not connecting to the server).

What about mail?

Most BlackBerry devices support IMAP as default mail protocol, which is much more efficient than syncing mail - as IMAP does not need to download the entire message if you do not need it. For mail push functionality, see /kb/idx/0/093/article/