I got one of these USBtinyISP kits.
The problem was that since I'm not using Linux as my desktop how can I get
avrdude installed on OSX 10.7.4? Then I immediately thought ... Homebrew?
Type the following in Terminal.app
$brew install avrdude --with-usb
Now lets connect to the ISP via avrdude and see if our LED's light up on the USBtinyISP
$avrdude -c usbtiny -p m8
If everything is successful you will see the following
$avrdude -c usbtiny -p m8 avrdude: initialization failed, rc=-1 Double check connections and try again, or use -F to override this check. avrdude done. Thank you.
Don't worry about the "initialization failed" message, this just means there's no chip currently connected to the ISP. You should definitely see the green LED go solid and the red LED flash when executing this command.