Most DRM schemes don't allow the casual user to create DRMed ebooks.
There is usually a central server in the loop some where. With MobiPocket you can create a DRMed ebook "template" but it has to be sent to mobipocket for customization for an actual device (1-4 device PIDs). With Adobe ADEPT the DRM is again controlled via Adobe servers (1-6 devices per account), but I'm not sure how publishers upload content.
If you are in the US, be aware of the
DMCA before researching DRM. There are similar laws in some other countries.