Scrum by the book says "Interactions over processes and tools" which kind of implies that tools should be avoided. This is plain easy when the team is co-located but how does it go when a team is spread over two to three countries?
It doesn't mean tools are to be avoided. The actual text of the Agile Manifesto, from which "interactions over processes and tools" is taken, says:
That is, while there is value in the items on the right, we value the items on the left more.
So we value individuals and their interactions more than we value processes and tools, but we still find value in processes and tools.
If your process or tool is intended to help individuals interact, I say, go for it. Electronic chat programs, Skype, wikis, forums and email have all worked well for me in those situations.