BT works, just get it.
I use Bluetooth for my wireless mouse and keyboard, and I use it with my SonyEricsson T610 and Salling Clicker. This is such a cool program, you can use the phone as a remote for iTunes, as a mouse, as a remote for Keynote or Powerpoint, etc. If you are playing music on iTunes, it mutes the song when your phone rings. I also use my phone as a modem when I'm out in the field and need a quick bit of data, so I dial into my account using the phone while it's sitting in my pocket.
Get it installed, its only 45.00 and you will find many interesting uses for it, you can get a phone w/ bluetooth later or a PDA, or even use it to connect it to other Macs or devices.
And having the dongle uses up a USB port and is yet another thing to have around.