Yes, the iPhone’s built-in browser offers grat support for JavaScript, and in most cases no code changes are required to make an existing website work with it. JavaScript can optionally be disabled from the Safari Settings.
The official specifications say the following:
The actual battery life will of course change according to your mix of wi-fi, iPod and phone functions. Our suggestion is charging (or synching) the iPhone overnight.
Yes it does.
No, it does support only 802.11b and g.
If you type an airport code in the Maps search box (such as “MXP” for Milan, Italy) it will center the map on the respective airport. From there, you will be able to quickly move to the city center. A list of airport codes can be found here.
When you connect the iPhone to iTunes, you have the option of synching contacts and calendars with Microsoft Outlook.
Unfortunately this is not possible right now, and no public announcements for a future support have been made yet.
Connect the iPhone to iTunes, then go the Photos tab, select the option box “Synchronize Photos”, and select the folder where your photos are located. Finally synchnorize the iPhone with iTunes by clicking the Apply button at the bottom.
iPhone batteries are not user replaceable. If your battery stops working while still under warranty, you can bring the iPhone to an Apple Retail Store or to an Apple Authorized Service Provider, and they will take care of replacing the battery (not immediately though, it may require some days). For out of warranty batteries, Apple made available a Battery Replacement Program, which costs $79 + 6.95 shipping.
iPodJuice is selling iPhone batteries directly to the customers, but you must be familiar with soldering to replace it by yourself, since the battery is soldered to the motherboard.