If you've got an Apple or Android phone, you might like this pronunciation application from Macmillan, based on Adrian Underhill's chart. I haven't got such a phone, I'm afraid, so I haven't been able to test it. If you have managed to test this application, please make your opinions known to us by commenting below.
Updated 26/04/2011: It has just been brought to my attention that the application is only available for iPhones at the moment. I suspect it's to judge the demand, so, the more people who download it, the quicker will it be made available for Android phones, too - that is my guess!
You can download it here:
Cockney Rhyming Slang
Pronunciation of regular simple past
Teaching and learning pronunciation
Transcribing text to IPA symbols