The other day I tried to purchase an album from iTunes through the Wi-Fi Music Store on an iPhone. Unfortunately, the transaction couldn't be completed because there wasn't enough storage space on the device. 8GB isn't what it used to be.

While it's easy enough to delete some photos (but only from the pictures you take on the iPhone itself) and e-mails (one at at time!), like with an iPod you can't delete audio files from an iPhone without connecting to a computer. This is frustrating for those who need to make space quickly, but mostly have music on their device.

But what if you've got some videos (an even bigger memory user than music) on your iPhone? Ah, well, that's a different story altogether. You can actually delete videos with no PC or Mac present.

Here's how to do it:

First, you can remove a video from your iPod after it finishes playing, for example. Simply hit yes when you're asked by a dialog box if you want to remove it.

You can also swipe a finger from left to right over a video title in the iPhone's video list. This will bring up a red Delete button - the same one you see when deleting an e-mail or a picture from the Camera Roll in photos. Tap it to continue deleting. Hit cancel if you've changed your mind.

Should you delete a video from your iPhone to save space, it'll still be in your iTunes library. So, if you want, you can sync it back to your phone again later on.