Here’s a great article on the ethical standards of Interaction Designers in the era of Ubiquitous Computing.
The actual ethics start about halfway down the page, but it’s a good read even before that.
To the ethics stated here, I would add:
Principle 6. Be Imaginative.* Do not create a system or piece of a system simply to for the sake of itself. If the “user” could make a cup of coffee (for example) just as easily without your system, then there’s no need for the system to be there. This may seem obvious, but why do I get the feeling that it won’t be in about 12 years?
WARNING: It’s gets a little technical for the untrained eye, so beware. All you HCIers, have at it.
* This is a shout out to Marty’s Computer Imagination, aka “The thing that HCI/d’ers should strive for.”