This blog on interstitial dwells between an inordinate number of other blogs and a plethora of information. Although space is the nature of interstitial, it's also about what can be created within that space.
Ideas are Interstitial: creative thoughts that dwell within the spaces of your mind waiting to be discovered. I believe there is a wide range of ideas that can be spawned by thinking interstitially - through creative associations in art, music, literature, etc. The possibilities are endless because even interstitial can be interstitial. Just think what dwells in less than 5% of the universe between all that mysterious dark energy and dark matter. It's amazing!