Part of Apple’s success has been its ability to reinvent itself and constantly update products, which is why yesterdays release of the free iOS 4 software update has caused such a stir.

The new update features the ability to create and edit custom playlists on your iPod touch, and sync and display nested playlist folders from iTunes.  Users will also be able to multi-task, running several applications at once. Which magazine reports that Apple have claimed there are over 100 new features with the ioS 4.

In terms of compatibility the iOS 4 software update works with the second- and third-generation iPod touch but Apple warns that not all features are compatible with all devices.  Wired Online have reviewed the update and they have found that it runs much faster than iPhone OS 3 and overall consider it a fanstastic free update.