A Google developer, formerly on the Android team, provides a detailed, fair, and clear explanation of how iPhone OS 4 multitasking will work. Robert Love explains the difference between true background application multitasking and Apple's limited set of APIs that let certain processes continue to operate in the background. He also differentiates serialization (quitting an app while preserving its state precisely) and true background operations. follow link
Option-Click AirPort Menu for Network Details
If you hold down the Option key while clicking the AirPort menu in Mac OS X 10.5 Leopard, you'll see not just the names of nearby Wi-Fi networks, but additional details about the selected network. Details include the MAC address of the network, the channel used by the base station, the signal strength (a negative number; the closer to zero it is, the stronger the signal), and the transmit rate in megabits per second showing actual network throughput. If you hover the cursor over the name of a network to which you're not connected, a little yellow pop-up shows the signal strength and type of encryption.
- ExtraBITS for 12 April 2010 (12 Apr 10)
Google Developer Explains iPhone OS 4 Multitasking