Why would you want to spend USD30 on a bus pirate if you can get a complete linux computer with 40 odd I/O pins with I2C / SPI / UART / ETC for less than that? (Gosh, there is a BeagleBone Pocket for USD 25).
I especially like the combination of the BeaglbeBone Black with a Linux host.
Just plug it into a USB port and then browse to it with your favourite web browser. Not even a power cable is needed.
Also no need to install drivers as (most) Linux distro's support HTTP over USB.
http://beagleboard.org/getting-started#step3For less advanced OS'es you need to install some drivers to get this working.
Another toy to play with those busses is a board like the ESP8266 or ESP32 in combination with micro python.
You can access it over WiFi with a web browser and use a terminal like REPL interface in your favourite web browser to execute lines of code on the ESP.
http://docs.micropython.org/en/latest/esp8266/quickref.html#webrepl-web-browser-interactive-promptFor ESP8266 I want to recommend the "Wemos D1 Mini". These are pretty small an cheap boards which fit directly in a breadboard.
They also have an onboard CH340 for communication / programming and are compatible with the "arduino" framework.