##
Some Voices of Reason:

A critique and
list of problems with
string theory as a theory of quantum gravity, from Warren Siegel's website. There you can also
get his book on string field theory and other important publications.

Work by Daniel
Friedan on a different sort of theory. The introduction has extensive
comments on the present situation of string theory.

A dialog written by
Carlo Rovelli presenting an impartial version of the lively debate between string
theory and loop quantum gravity.

An assessment by Lee
Smolin of the state of research in quantum gravity, including a careful
consideration of the state of string theory as a quantum gravitational
theory.