I just found this the other day, have been playing with it and now it's time to recommend it!
The app is called Dock and I think it was just updated recently to run on the iPad.
It allows you to (1) load as many icons (apps) you wish on a shortcut-like dock that accessible anywhere on the iPad. You can open/close apps, background apps, close backgrounded apps and switch between apps. I've stopped using Mutlifl0w, an appswitcher, because I like the looks and appearance of this Dock better.
The only thing about it is that you can tell it's a fresh make for the iPad because it only opens on one long side of the iPad (the right side if the iPad is in portrait with the home button on the bottom). I've written the developers and they say their plan is to make it so the Dock rotates with the iPad. We'll see...
But, it's perfectly usable as it is and, as I said, I prefer it for switching between apps.
I've attached a link to YouTube where I've made/uploaded a video showing what this does. Here's the link: [ame="http://www.youtube.com/watch?v=rOYorrf3Fek"]Cydia Tweak: Dock (on iPad)[/ame]. I would have just made screenshots, but the Dock closes with a home screen button press ... no pictures possible. Thus, the video.
You can download a free 3-day trial from Cydia (obviously, it's only for jailbroken iPads). Then, if you like it, it's $4.99 (USD).
I am unsure if it'll work on iOSs higher than 4.2.1, but with a free trial, you'll not lose anything if it doesn't.
I like this for app switching and prefer it. But, and as always, YMMV.