Third party solutions
In my experience, BlueHarvest is best in class. Technically, it is not an answer to the question; it can remove but not prevent .DS_Store files.
If BlueHarvest is effective but does not suit your use case, it becomes difficult to give an acceptable answer to your question.
If you have no acceptable third party solution, then you must work with what's integral to Leopard …
Without a third party solution: restrain your use of Finder
By avoiding the views that you do not wish to save, you can prevent creation of .DS_Store files.
Most users will find it difficult to restrain themselves in this way, but it's a true answer within the limitations of the question.
http://diigo.com/0qiwp for an annotated view of http://lists.apple.com/archives/applescript-users/2006/Jun/msg00180.html where Matt Deatherage (a former engineer at Apple) explains .DS_Store and other types of file.