My K3 went to eBay 3 days after I rec'd the Nook Touch.
Meanwhile, back here in reality, on a Mac you download (and please contribute for) calibre, and likewise DeDRM.
The latter provides plug-ins for calibre which remove the DRM when you import a book into calibre, and you can then convert the book to epub, with options to remove publishers' margin settings, etc.
PDFs remain an issue, as the Nook Touch support for PDF is offal (sic).
I treat all my Kindle ebooks this way, and read them on the NT. I prefer to buy ebooks from Amazon, as their storefront is much more functional than B&N and others.