One of the more difficult things a writer can do is write about a culture that is truly alien. A lot of bad SF— especially in TV and movies— has shown alien beings that are significantly less alien to someone from a western culture than many human cultures.
My own personal shortcut to the problem of envisioning an alien species is to take some universal base-line facet of humanity and changing it, following the change to its ultimate conclusion. Changing the method of reproduction is one possible change; altering the method by which young are produced will change everything in a society. (Consider how much of human religion is dedicated to sex and gender roles.) Altering the primary method a species receives sensory input is another radical change that would produce profound psychological and cultural differences.
Another possible change, and one that I believe has some implications for the future of our species, is altering the species’ primary means of communication. The most alien of the aliens I have written about are the ghadi in Broken Crescent. The ghadi were a whole species as intelligent as man, but suffering a universal aphasia that removed the capability of verbal and written language. They end up thinking in a way that is completely alien to us.
More concretely, a change in the means of human communication— movies, television, and the mass-media— has caused radical and wide-spread permanent changes in human culture. One of the more profound effects being the ability to propagate a culture beyond its physical boundaries without force of arms. What the Romans did with legions, we do with Nike and Keanu Reeves.
Consider now this blog. The ability of one person to conduct a dialog with an entire planet. It isn’t clear where this will lead, what is clear is that we have no idea as a society how to handle it. The idea of public and private speech is obsolete on the internet. Your employer can Google you and uncover every stupid inappropriate comment you ever made on a Hello Kitty website. You drop a shopping list and someone can post it on—line. You can get fired or expelled because you scared someone in authority— and you can’t take back those electrons.
The more we communicate by text and e-mail, the closer we come to a scary point of universal selective omniscience. When we speak, we speak to everyone, and we can find out everything about anyone we want. What then?