I use SpringPad or EverNote, but not for handwritten notes, I type out my notes.
There are no such beasts I am afraid. Back in 2006-8 I had a tablet pc with an active digitizer and that worked "fairly" well. Not even an iPad would give you the desired effect of hand-writing notes. That is why I chose a Nook HD+. As a grad student it would be nice to have something to write on PDFs and PowerPoints but that won't happen without paying over $1200. You COULD get the Boogie Board Rip for jotting down notes but it only saves files one PDF at a time per screen (think of it as a blackboard, everytime you save it saves a file and wipes the screen).
ePDF Reader has a marker feature that is thin enough to write on but any stylus lacks the coordination to make any progress.
So to answer your question: no, there will never be any app for touch-screen tablets that will serve our purpose in taking notes without our palms interfering and to have legible hand-writing.
The Samsung Galaxy Note 10.1 tablet does hand-writing natively and it comes with digitizer stylus-pen plus great note-taking software pre-installed. Also, if you root your Nook Color/tablet/HD/HD+ to get access to the Google Play store you can download an app called Genial Writing. It is great at hand-writing notes. You will need to purchase one of those rubber-tipped stylii or other compatible stylus but it should work quite well. Also, the Asus Eee EA-800 Note is an 8inch tablet-like device that does hand-writing natively as well. It also comes with a stylus. It is a non-backlit LCD screen in grey-scale; similar in look to E ink so, no color; but it has great hand-written note-taking software as well. You have to order it off of e-Bay to have it shipped in from Taiwan as it was never sold in the US. I have one and love it. It is a pretty handy little device. It also doubles as an e-reader and has a fairly decent rear facing camera. I have used all of the above methods so I can honestly recommend them. All of these methods/devices address the palm-rejection issue effectively. I do a lot of journal-writing and nothing beats the visceral sensation of a pen in my hand as I write down my thoughts. Typing just doesn't do it for me. I hope this helps.