TITLE: Probabilistic (and other mathematical) methods of physics without the physics?
QUESTION [13 upvotes]: Many of the methods of physics are vastly more general than their use in that discipline. For example, information theory overlaps with a lot of statistical mechanics, and the latter actually developed first. ET Jaynes wrote a famous paper illustrating the connections. However, each is comprehensible without the language and intuition of the other (though I do not deny that a richer understanding comes from knowing both). 
What other methods of physics (particularly those with a statistical or computational bent) have interpretations (Please mention useful introductory texts!) that are completely physics free? I understand that various field theories meet this criterion; any good non-physics introductions?

REPLY [2 votes]: I found Complexity and Criticality by Christensen and Moloney to by quite excellent.  It gives a much more computational approach to  the percolation phase transition, the ising phase change and issues of self organized criticality (via the sand pile and rice pile model).
As a computer science student, I found this book to be invaluable for my work on phase transitions of NP-Complete problems.