Apple added native multitasking in iOS 4.0 but some of us dislike it as it takes our options away from using our double tap home for shortcuts such as open favorite contacts, or ipod. For us jailbreakers we have an option to disable multitasking and its a simple plist edit in the system file, don’t worry i’ve done the hard work for your.
Just add TheSpot’s repo above to your cydia sources and install disable multitasking ios 4 from iphonespot apps section and enjoy your iphone without multitasking. This is mainly for those with the iphone 3gs. If you want multitasking back you can simply uninstall this tweak using cydia and you’ll be back to normal.