Private Language - http://plato.stanford.edu/entries/private-language/ Entry from the Stanford Encyclopaedeia of Philosophy.
Hacker on a Private Language Argument - http://easyweb.easynet.co.uk/~thonemann/privatelanguage/plliterature/hacker.html A critique by Philip H. Thonemann of an account by Hacker of the use Wittgenstein makes of ostension in his private language argument.
Wittgenstein's `Private Language' Argument - http://www.rbjones.com/rbjpub/rbjcv/papers/ugp01.htm Undergraduate essay by Roger Bishop Jones commenting upon the PLA by attention to sections 243 to 264.
Wittgenstein sans The Private Language Argument - http://www.ul.ie/~philos/vol1/wittsan2.html Stephen Thornton argues that the private language argument is less important to Wittgenstein's broad conclusions in the Investigations than is commonly taken to be the case.
Wittgenstein on Rules and Private Language - http://krypton.mnsu.edu/~witt/ The `ultimate homepage' by John Humphrey. A comprehensive and critical survey of Kripke's book by the same name. Its aim seems to be to finish off Kripke's position in that work.