1. Multitasking .: As you know apple introduces Multitasking recently which was a great improvement and a very nice feature from all the aspects so accessing recently used apps and doing multitasking can be done through this simple Home Button. User have to double click the home button to access the recently accessed apps menu then he can either click or hold to close the apps from this menu for gaining some more RAM.
2. Controlling your iPod and Locking Orientation .: Well now you can double click your home button than simply drag right to get the iPod control menu , from here you can control your iPod music giving your music time a FUN Time and this also contains a Orientation locking button which helps you to lock your orientation so that as soon as you tilt your iPhone will not automatically change its alignment.
3. Voice Control Feature .: Voice control feature is really impressive on iPhone. The other phone which has some superior feature like this is Blackberry well with this feature you can simply call anyone, dial any number, play music and do much more its really a superior which you all should use to make some more from your iPhone.
4. Capturing iPhone Screenshots .: Capturing screen can be really useful as you can see all the screenshots above these are taken by this unique feature how to use tis feature is you have to click HOME + LOCK button together @ the time you want to take shot it really helps you demonstrating any new app or any other thing to anyone by just taking simple screenshots.
5. Stuff Searching feature .: when you are default home and you simply press home one time or [simply drag your screen to right you Weill have access to the iPhone searching feature which is also really and really indexed everything quit well you just have to type the thing you are searching it could be music, message, photo, app or anything it will search everything so you should also check this feature out.
6. Forced Shutdown .: well in any case your iPhone is strucked well it will never but in any case you are using 2nd generation or 3 generation they have some small ram and are quit slow so you may have hanging problem sometimes so pressing HOME + LOCK continuously will help you to force shutdown and make your iPhone well.
So have Fun using all this alternate features with Home button and feel free to comment if you some errors or problems or question you wanted to ask.