They say space is infinite but my MacBook and iPhone disagree. I have been living with a MacBook that has about 5 GB of space that I use to swap around temporary stuff but yesterday some mysterious process unique to the Mac philosophy gobbled up what was left. I suspect the culprit magically whisking away space on my iPhone is Spotify.
The remedy I settled on was to download even more software. Firstly I fetched GrandPerspective that may not be the best tool to investigate disk usage but it is free and the first I found. With its aid I found and deleted about 16 GB of stuff and even though it was just mere minutes ago I barely remember what it was but amongst the things gone were installation files for Xcode extra stuff iPhone backup files, all iPhone apps stored in iTunes, iTunesU videoes, and other Steam and some other huge software packages I never use.
For the iPhone the solution was to get the latest version of Spotify where they have actually implemented the system that deletes songs you choose not to have available offline. So now I have two GB free on the iPhone as well.
Better download something.