• Improve your Edge Network speeds.
This revolves around the black plastic part where the antenna is placed. If you take your hand off the antenna (i.e. bottom part of the iPhone) then you will observe not only an obvious improvement when you have low signal strength but even with a full signal one should see up to a 25% increase in Edge speeds. Cellphone signals have a hard time going through your hand. In fact, your hand must remain three-quarter inches away from the antenna or you exceed FCC limits for radio exposure.
• Yahoo Messenger Workaround
Since the iPhone does not support 3rd party messenger services, the fine folks at Yahoo have a "http messenger" up and running.
http://m.yahoo.com/p/messenger
• Adjust the Screen Brightness
Each time you unlock the phone after waking it the light sensor samples the ambient light, and adjusts the brightness. But it does this only once and you can use it to your advantage. By covering up the sensor (just above the earpiece) as you unlock the phone, you force it to a low-power, dim screen-brightness setting (because the phone believes that it’s in a dark room). Or by holding it up to a light as you wake it, you get full brightness. In both cases, you’ve saved all the taps and navigation it would have taken you to find the manual brightness slider in "Settings".
• Mark Read Messages as Unread
When you are viewing a message, you can tap on "Details", which reveals a "Mark As Unread" option. Tap on it and the next time you view your inbox the message will display a blue dot, which indicates that the message has not been read.
• Three ways to scroll through your contacts
1) Flick your finger on the list to scroll up or down.
2) Tap on one of the letters in the alphabet running down the right side of the screen.
3) Hold your finger on the alphabetical list, and then slide up and down.
• Google Driving Directions Fast
Both the starting and destination fields offer a bookmarks icon. Bookmark your addresses so that you can use them to find directions a lot faster by avoiding all the typing.
• Web applications for the iPhone
The Apple list of Web applications for the iPhone can be found at
www.apple.com/webapps/
• Force quit an application
If an application is giving you problems, click and hold the Home button for at least 6 seconds. Follow the prompts from there.
• Force reset a frozen iPhone
If your iPhone locks up, try clicking and holding both the Home button and the sleep-wake button at the same time, until the screen goes black.