Apple unveiled its new iCloud service earlier this week at the company’s annual World Wide Developers Conference in San Francisco. One of the features CEO Steve Jobs touted was the ability to re-download app and music purchases without having to re-pay, and instead of having to wait until this fall when iCloud officially launches, we can start playing with previous purchase downloads now.

Accessing your previously purchased content, whether it’s apps or songs, is easy to do. Here’s what it takes, for example, to download apps you already paid for:

• On your iPhone, iPad or iPod touch running iOS 4.3.3, launch the App Store app.
• On the iPhone and iPod touch, tap Updates, look to the top of the list and tap Purchased. On the iPad, tap the Purchased option on the tool bar at the bottom of the app display.
• Apps that aren’t installed but are available since they were previously purchased include an iCloud download button. Just tap the button to start the download.

Look for the Purchased and Download buttons to re-download apps and songs

Downloading previously purchased songs works pretty much the same:

• Launch iTunes on your iPhone, iPad or iPod touch.
• Tap Purchased in the toolbar at the bottom of the app display.
• Just like apps, purchased music that isn’t on your device includes an iCloud download button. Just tap the cloud button next to the tracks you want to add to your device.

Re-downloading apps isn’t new, although offering users a clear way to tell what they have purchased — along with making it clear that re-downloads aren’t new purchases — is a refreshing change to the interface Apple previously offered. Letting customers redownload music for free, however, is new and long overdue.