I've done a search and not seen this mentioned, although I'd have thought it has... I've crammed my iPhone full of music, videos and photos, so it's now full. The phone now says "warning - you're running out of disk space, please delete some..." Which is obvious enough. Presumably the OS needs space for swap and mail. But my question is, how much is enough? I want to fit as much on as possible, without making it flaky(ier) to use. 100MB free? .5gig free? Any thoughts?