International Phonetic Alphabet (IPA) Unicode “Keyboard” - A Unicode replica of the official chart written in XHTML/CSS and released under the GPL. Allows the user to type strings of IPA characters while keeping track of previously used symbols and optionally outputting XML entities.
The IPA in Unicode - Unicode standard used by current browsers covers all the IPA phonetic symbols. Listed with their meanings, codes, and advice on Unicode fonts that contain them.
IPAScript - Description and online Demo of an input system for generating IPA symbols from SAMPA (Ascii) keystrokes
Say... - Text-to-speech translator which also reads ASCII representations of the IPA.