I recently read (in Dawkins' The Ancestor's Tale) about the Alu sequence, and went on to read about transposons generally. Having as I do a rather broad definition of life, I concluded that Alu (and others like it) are lifeforms in their own right, although parasitic ones. I found the potential ethical implications somewhat staggering, especially given the need to shut up and multiply those implications by the rather large number of transposon instances in a typical multicellular organism.
I have written out my thoughts on the subject, at http://jttlov.no-ip.org/writings/alulife.htm. I don't claim to have a well-worked out position, just a series of ideas and questions I feel to be worthy of discussion.
ETA: I have started editing the article based on the discussion below. For reference with the existing discussion, I have preserved a copy of the original article as well, linked from the current version.