Apologies up front if this tip has already been submitted. I did several searches and didn't find anything so straightforward! The tip comes from Ken K on macintouch.com: It saved me 21 GB... "Ken K: "Disk space recovery tip... Probably this has been mentioned, but here it is again. "I just recovered 20 GB of disk space on my MacBook Air by deleting old, useless iPhone backups for phones I don't even own any more. If you are pressed for disk space - I was down to under 1 GB on my Air! - you might give it a try. Of course, I'm sure some of you keep your machines perfectly up to date and don't have any old iPhone/iPad/iPod backups. But I hung onto the old ones during transitions to new devices, then forgot about deleting them. "To see which iPhone / iPad / iPod backups are old, open iTunes and go to iTunes > Preference > Devices. But iTunes doesn't show you the size of those backups, darn it, just their dates. "To see which backups are huge enough to be worth deleting: in iTunes, control-click on the name of one of the backups, and choose "Show in Finder." You will see all of the backups and can easily see their sizes. "To delete the huge, useless backups, go back to iTunes > Preferences > Devices, and compare the dates carefully to the dates of the Backup folders. In iTunes, delete the backups you don't want, then click OK. Bingo. Instant large increase in available disk space.