Can you damage your iPhone by charging it too often?

I've recently bought an iPhone 4S and I'm really worried about damaging it. Could it get damaged by charging it too often? Or could it get damaged by using it too often? Is it good to let it run completely out of charge from time to time? I make sure I turn it off every night to try and stop it getting ruined.

No all phones need charging and i'm constantly charging my galaxy S2 and its fine and i'm constantly on it so no it will be fine!

You Iphone will not get damaged by charging too often.
Your battery may get damaged, as a result you will get a low backup

On iphone you do not need to let it run all the way to 0 like some batteries have to do. I always recharge mine when its around 20%, and I always charge it overnight and have always had a areally good battery even after several years of doing this… Neither causes any problem.

Yes if you charged it constantly (15+ hours per day 6/7 days a week) it might over heat and become damaged.

No but all batteries do lose capacity over time.

My rule which works fine for me and always has is use the phone as normal in the day then plug the phone in when you go to bed and leave it over night until morning.
I have done this with every iphone i have ever had and i have owned them all and i promise i have never had a days problem with the battery.

YES
WHAT YOU DO IS OVERHEAT/EXHAUST THE MEMORY UNIT AND THE WHOLE THING.
EVENTUALYY IF YOU KEEP DOING THIS YOUR IPHONE WILL START TAKING MORE TIME TO CHARGE AND IT BECOMES WEEK

You won't damage it if you charge it too much or if you leave it on all the time, but make sure you don't leave it on charge over night as it could overheat and cause sparks