Over at Macworld, TidBITS editor Glenn Fleishman explains Apple’s curious statement that GPS positioning would take minutes without its secret sauce of Wi-Fi network and cell-tower location data. Apple (and other mobile device makers) supplement GPS with several clever techniques to get a faster fix. follow link
Single Time Machine Backups
Tired of Time Machine running all the time? You can turn it off in the Time Machine preference pane, but still initiate a single backup by choosing Back Up Now from Time Machine's menu bar icon. Of course, your backup is much less likely to be up to date, but Time Machine won't be taking any resources while you're trying to work.
How the iPhone Supplements GPS