Here's an app running. When you approach your thumbs anywhere near the corners of the device, the four hot corner icons would appear. On the top left, there's the close app icon. Click it and...
... the application will close.
On the top right there's the Exposé icon, which will show you all running apps, neatly aligned on the tablet. One click, and bring the app to the front.
On the bottom left corner, you can access the home button, which will bring you to...
...the home screen, with all the icons, just like the iPhone.