I have 10.5.6, and there definitely is a way to initiate the connection. You can either go from the Bluetooth icon in the system tray or go to System Preferences > Bluetooth and then click on the device you want, tell it to connect, etc. Also, there it should show the services it sees on the device. For my N810, it calls its type "Combo" and lists "BlueZ HID mouse & Keyboard" and "OBEX Object Push" in its Services.

Hope this helps. Sorry I haven't actually got my N810 on me to mess with it, but I assure you that it works (and has consistently and repeatedly).