I love using the ipad as a sketching tool. I often take it on trips and try to do CAD work on it. There are a few apps here and there that are useful but not great. I have been using touchdraw and sometimes inkpad If anyone knows of a good vector editing app please let me know. I also use a few sketching apps. For everything I use the Idonit jot pro
Also, I just saw this video for printing out your sketches. Not too bad