In iphone os 3.0 there were many changes.Some applications of iphone are really slow and some also decrease the performance of the iphone.so we need to quit that iphone app to make our iphone 3g fast and better to use.
Force quitting option is really useful to stop those applications which tends to be head ache for iphone users.
How to force quit an iphone app:
Press and hold the sleep/or wake button and you will see the .....

