I've been looking for the same thing. I found a program called DrawFree. It's a drawing/note taking app that so far is the only one that performs well. The other note programs I found all had a bad delay as you were writing. It saves the drawing/notes as a standard PNG file that can be opened on anything.
There was another porgram that looked very promising that was called MyLetter. It has a lined notepad type layout. The problem though, and it could be user error, is that when I write and then save it (you have to click a check mark off) it saves the writing really really tiny..barely visible.
I am sure that ones the HTC Flyer tablet comes out there will be developers that will copy the note taking program that comes with the Flyer as that si suppose to have a nice one in it.