Leaps and bounds above the 3g model i used to have, the 4s has a very high definition screen. The glare on the screen is acceptable but in heavy sunlight it is hard to read smaller text.
The phone comes with apples built in apps which allow you to get started straight away but by using the app store you can download a program for just about anything. Some of these programs, or apps as they are called, are free. Some of which are not, but even the most expensive applications charge only a few pounds. Battery life is not great when in use and you can blitz the battery with a few hours of 3g networking but it will usually last a day through normal use. On the plus side though the charge time is under two hours so if you carry your charger with you it does not take long to charge at work for example.
The phone is easy to use, yet advanced enough to compete with a computer for every day web tasks. I use this phone for just about everything from around the house to work related tasks.
The phone also has a music app built in turning your phone essentially into an ipod which is a great feature especially for those models with larger built in memory.
Unfortunately the worst thing about the iphone still remains, you can not upgrade your memory and there is no slot for a device such as an SD card either.