Wednesday is a big day for iPhone and iTouch users as Apple releases it much-awaited OS 3.0 for the units, adding a slew of new functions and improvements.

The update will be available free from iTunes for iPhone users, and iTouch users can grab a copy for $9.99. Apple has yet to announce the time of the release.

OS 3.0 will now allow users to send multimedia messages (users can now send photos, contacts, audio files, and map locations), do voice recording, buy and rent movies and TV shows over the air, full system search, tethering and push notifications.

Some features will be carrier dependent though – AT&T won’t offer multimedia messages until later this summer.