The I2c-tracer. This is a piece of supporting hardware. There is also in the software part (examples/bascom) a I2c-locator that doesn't need any additional hardware. With the I2c-tracer hardware you can do more than just locating the I2c-dvices on the bus.

The I2c-tracer

Image of the I2c-signals on a scope.

Software for the I2c-tracer
I2c-tracer.
Check with the Seek command your I2c-IC's on the bus. Not working on a live bus. (shareware)		 I2c07BS.zip