[Bluetooth dongle idea]

Look into an input stick.

http://inputstick.com

APIs are also available for creating custom apps.

[Booting Linux on Apple Laptop Hardware With a USB Key]

Formatting the USB as FAT is worthless because you are blasting over the file system with the ISO data. Just FYI.

Tried doing it when it was formatted as HFS+ and it dd utility didn't like it for some reason and it didn't work. Not sure why...

[Booting Linux on Apple Laptop Hardware With a USB Key]

I was able to successfully do a live boot from USB from an .iso image using dd utility

1. Formatted USB Drive as MS-DOS (FAT)

2. Unmounted the drive (in this case mine was disk1): diskutil umountDisk /dev/disk1

3. Using dd utility, put iso on USB Drive: sudo dd if=linux.iso of=/dev/disk1 bs=512 conv=noerror,sync

USB Drive is labeled as Windows in the Startup Manager

Boot was successful, Drivers are a different story...

Drive created on Mac OS X 10.9 (13A524d)

Test System: MacBook Air "Core i7" 1.7 13-Inch (Mid-2013/Haswell)

Distro: Kali Linux 1.0.4 amd64

[Booting Linux on Apple Laptop Hardware With a USB Key]

Are you looking for a live boot of linux from USB or a bootable install from USB?