I have an I2C peripheral that I need to interact with using a Windows 7 PC. The interaction could be through a terminal emulator, or any program that can produce a real-time log that I can process using a scripting language. Based on your experience, what is the least painful way to achieve this?
In my experience the easiest way is the Bus Pirate, which is also a cheap alternative: http://www.seeedstudio.com/depot/bus-pirate-v3-assembled-p-609.html?cPath=61_68
You can find a good tutorial for it: http://dangerousprototypes.com/bus-pirate-manual/i2c-guide/
And people in forums such as this is are familiar with it. For hobbyists, bus pirate is the way to go.
I would use the ATMega chip from an Arduino Uno, or the Arduino itself. It is easy enough to interface via a terminal from a PC, then link commands from the terminal to the Arduino and have it do things with the I2C bus.
Examples abound in Arduino land...