Today, Steve Jobs unveiled the new iPhone 4 during Apple's Worldwide Developers Conference in San Francisco. The phone, which is both slimmed down and more industrial looking, is slated to go on sale on June 24. You'll pay $199 for a 16-gigabyte model and $299 for a 32-gigabyte model with a two-year AT&T contract. Here are some of the highlights:

Retina display: The phone's ultra high-resolution display has 326 pixels per inch, four times as many as the current model, the iPhone 3GS.

Video calls: Users can now make video calls using a WiFi connection. The phone has a front camera and a back camera, allowing the person on the other end to watch you or see things from your viewpoint during video chats.

App folders: You can now organize apps into folders automatically labeled by category (e.g. travel).

Streamlined e-mail: The phone lets you view messages from multiple accounts in a unified inbox and organize message threads.

Souped-up camera: The iPhone 4 has a 5-megapixel camera and an LED flash for taking photos in low lighting. You also can record high-def video in 720p and edit it on your phone with the iMovie app.