The Total Phase I2C/SPI Activity Board is a perfect tool for both the expert and novice embedded systems developer.
This board is a great sanity check for the expert developer. Debugging a system against working slave devices can help differentiate between hardware and software bugs. The activity board is also useful to establish a baseline for software usage.
The target devices on the activity board are also a great way for the novice developer to learn the mechanics of the I2C and SPI bus protocols.