Apart from being a great unit to hold, listen to and play around with, we've found the loops generated can have some practical uses too.
Some tracks when played very quietly, barely audible can create a 'softening' ambient space following a line taken by other ambient works. For further info on this wikipedia has a great piece on Brian Eno and his inspiration for Discreet Music.
I've found that very young children/babies relax to the sounds generated and it can soothe them when they need to sleep, or settle them down to drink milk. Think of it as a permanent nursery mobile. Older children just love playing with them as much as adults.
I also hear that track9 is particularly good at keeping cats away :)
If you have found any other uses you would like to share, please contact us, we'd love to hear what you are doing with your machines!