The wizards at spark fun proably already know about this but I like it especially because my laptop does not have com ports.
Ok their octopus is also interesting especaly with the idea of compiled java, java GUIs’ and a nice interface for hardware.
It can be a programmer debugger general purpos IO, RS232 to USB CDC class, converter JTAG
It can be programmed in C JAVA python to control GPIO
Also logic analiser in beta and pic programer in idea.
any ft2232 based device such as the TInCanTools Flyswatter or the Olimex USB OCD devices can be used for more than just JTAG. the ft2232 supports SPI,I2C and GPIO as well as the basic JTAG.