Wacom have just released a full featured note-taking iPad app. It's free until the end of June, so go get it now.
You can scribble in 6 colors, 3 thicknesses, and you can also erase. There's undo/redo options, which is a pleasant surprise.But the more important detail is that the curves are smoothed out, which is more than I can say for most sketching apps.
Sharing options include emailing the current page, saving it to your photo album, and printing the page. You can also email an entire notebook as a PDF or print it. Curiously enough, the free app appears to only have the one notebook. This is going to cut into my ability to organize.
The one downside for this app is that it really wasn't designed for a fingertip. It requires a finer degree of control than I'm used to using on the iPad. Apps like this are why I got a stylus for my iPad. I don't know anyone else who has one but I also knew it was a good idea.
BTW, Wacom are using the free app to promote their $24 iPad stylus. Trust me, you don't need to spend that much. You can find quite adequate styluses in the $5 to $10 range.
Nate Hoffelder is the founder and editor of The Digital Reader:
"I've been into reading ebooks since forever, but I only got my first ereader in July 2007. Everything quickly spiraled out of control from there. Before I started this blog in January 2010 I covered ebooks, ebook readers, and digital publishing for about 2 years as a part of MobileRead Forums. It's a great community, and being a member is a joy. But I thought I could make something out of how I covered the news for MobileRead, so I started this blog."