Justice Ginsburg of the Supreme Court of the United States recently made comments about the use of decisions of foreign law courts in U.S Court decisions. You can read an article about her comments here in a posting on the Wall Street Journal Law Blog, along with debate pro and con.
I tend to agree with Justice Ginsburg. Why would cut ourselves off from any information that might be helpful as we strive to make the best decisions we can. That does not make decisions of foreign courts binding, or even persuasive: they are not. Judges have always used dictionaries, literature, historical events, art, poetry, and other resources to inform their decisions, or as background to understanding an issue. I do not see much difference. If it helps, use it. If it doesn’t, ignore it. US Law is still binding.