There is a new tweak in the Cydia Store called, Switcher Rotator. Switcher Rotator allows your multitasking switcher bar to appear in either portrait or landscape mode. It also enabling you to lock your device orientation into landscape mode. Switcher Rotator works with many popular app switcher tweaks such as SwitcherMod, SwitcherPlus, SBSwitcher, and more.

Switcher Rotator requires iOS 4.2 or higher and is not compatible with the iPad. No new icons are added to your homescreen. There are no options to configure.

You can purchase Switcher Rotator for $0.99 in the Cydia Store via the BigBoss repo.