This awesomely handy site includes a phonemic keyboard for putting symbols in your essays easily, but also has clickable phoneme test and a downloadable pdf of flashcards.
You can also find a clickable phonemic chart here... use headphones, or prepare to be looked at weirdly as your computer says /ɪə/ ... /ɔ:/ ... /u:/ ... /ʧ/ ... etc. :)
