One of the most lauded features of the Touchpad and other WebOS devices is the card based multitasking. It's both useful and beautiful to page through your open applications all minimized like a deck of apps.
Several Cydia tweaks have come along to simulate the same ability. There is MultFlow which has a similar card view option, older Proswitcher and the newly developed CardSwitcher which is unfortunately incompatible with iPad.
Today a new tweak is out called LameSwitcher which is both faithful to the WebOS format and compatible with iPad. You can set up the program through your settings tab enabling several options including a full selection of activator options to pull up your cards. Also, exactly like WebOS, you can simply drag the card to the top of the screen to close your program.
The best feature of this app compared to the others? It's free! I've been using it on my iPad 2 today and it seems to work without a hitch. Give it a shot!