Would I be able to run both an I2C compass/accelerometer/gyro (https://www.pololu.com/product/2470) AND a string of four-wire LEDs off a Bluno Beetle (http://www.dfrobot.com/index.php?route=product/product&product_id=1259#.VdCAEcSkqrW) which only has one I2C/SPI pin?
Sure, it’ll just bitbang the 4-wire output. Though, the bluno is. 328/32u4, right? Could probably use the uart in spi mode for pushing out led data 
I think that might already be how the Bluno talks to its BTLE chip (that it can do over-the-air sketch uploads is a hint?)
But good news. Hmm. I fear I may just have another life-consuming project here. (After poking around and speculating on a rough BOM, I see why existing “smart” juggling clubs are so expensive—those gyros add up quick…)
@Robert_Atkins I have used this accelerometer
Just posted for you an example with this I2C accel in combination with bitbang