One great note taking app I use all the time is called Notebook by a company called Circus Ponies. Notebook looks just like a paper notebook and lets you take notes while it records the speaker, so you have an audio record of the meeting (great!). I use it to organize client information and keep track of notes, PDFs, emails, proposals, everything. You can take notes, create diagrams, scribble on the pages. You can even add a PDF as separate pages in your notebook and then scribble and take notes on top of the PDF pages. It's really great having everything all portable and organized on my iPad. Definitely an app worth checking out!