The other unofficial standard for mapping IPA into
ASCII is, surprisingly enough, called IPA/ASCII.
IPA/ASCII is the de facto standard on Usenet
and to a lesser extent on the Web, although the advent
of Unicode (which includes all IPA characters)
will hopefully eventually obsolete such
kludges.
At any rate, the entire IPA/ASCII standard
has been noded for the pleasure of all you cunning
linguists.
There are quite a few similarities to SAMPA, but
still enough differences to keep you on your toes.
Standards are wonderful, there are so many to choose from...