Gizmodo has an interesting article about many of the iPhone features that are introduced in the 3.0 update, and how you can get many of them right now via jailbreaking and Cydia. Many of the features mentioned in the update have been available there for awhile now, albeit not in easy to use form.

This article: http://i.gizmodo.com/5175586/how-to-fake-the-iphone-30-os-on-your-iphone-today lists all the apps that mirror many of the 3.0 features, and links about how to jailbreak your existing 2.x iPhone so that you can run them.

Most of the apps are free (or only a few dollars), including turn-by-turn GPS, copy and paste, tethering and e-mailing multiple photos, among other 3.0 promised features.

Feel free to take a look, but make sure you know what you’re doing before attempting to jailbreak your phone. Making a mistake doing this could potentially damage your iPhone.