When I purchased my Dell Inspiron 1420N with Ubuntu pre-installed, bluetooth was not offered as an option. It seems it still is not as of today.
The machine does have a nice built-in slot and connector for a bluetooth module. It seems the Wireless 355 Bluetooth Module is the right one, even though the Inspiron 1420N is not listed under compatible systems. I purchased one – it fits perfectly, and it works pretty much out of the box.
I installed the gnome-bluetooth and bluez-gnome packages, and was able to pair my phone (just type any code on the phone, only then the corresponding dialog will show up on the laptop) and send files from my phone to the laptop.
And if you install gnome-vfs-obexftp, you can simply browse to obex:// with Nautilus, and browse your phone as a hard drive. Works like a charm, and again, out of the box with my Nokia E70.
Which makes we wonder why, exactly, this bluetooth module is not a preconfigurable option on the 1420N?