samsung galaxy ace - Application to switch among multiple running applications

I have Samsung galaxy ace with android 2.2 mobile.

Is there any way or any application so i can run many applications simultaneously and i can switch among them?

Why do i need this.

1. When i surf facebook(or any other application), and i click on a link. I am suppose to wait until the page gets opened then i read it pess back button to reach on previous button. If i press previous button in between i'll lost page which was being loaded.


2. If i read some sms, and i have to search the meaning of a word in dictionary, i would have to exit from sms box.

Answer

Case #1: You can get back to recently used apps by holding down the home key until a menu appears, and then selecting the app you want to return to.

Case #2: Press the home button and open your dictionary app, and then use the method in #1 to return to messaging.

This works if you don't have too many apps open, since the memory is limited and if you open too many apps, android will close them from the background.

The important distinction is that the home key does not quit the app but exists to the launcher, and the back button exits the app.