Manning and Sitepoint also offer DRM-free ebooks. I have a Nook and I do not buy any books through B&N.com, only direct from technical publishers that are DRM-

Manning and Sitepoint also offer DRM-free ebooks. I have a Nook and I do not buy any books through B&N.com, only direct from technical publishers that are DRM-free and then load the epub file via USB. In fact I only turn my network connectivity on about once a month to update the clock on the device.