How do I switch apps on a Samsung Galaxy S2?

We all like to multi-task where we can and we love to save time, so being able to swiftly switch between apps on your phone is almost a must. On the Samsung Galaxy S2 it's incredibly easy to switch between recently used Applications.

If you hold the "Home" key on any screen for more than a second or two you will see a screen like the one on the left here. If you press on any of the applications shown on your screen (which are the last 6 applications you've you've used) you can switch directly to that with out needing to go back to the home screen.

In this example we could switch to the music to change a song, then switch to Facebook to check any status updates and back to Opera quickly and easily.