I have had the same problem before. Wiped out my device. Hasn't happened again. One time, I had 10 gig of "Other".
The filters Apple built into IOS 3 and up watch for meta tags from porn sites, Caches, vids and pictures with a meta tag of, say, "youporn.com" constitute the bulk of "other".
The filters Apple built into IOS 3 and up watch for meta tags from porn sites, Caches, vids and pictures with a meta tag of, say, "youporn.com" constitute the bulk of "other".