The Color Vowel Chart

What a great tool for learning the differences in vowel sounds in American English!  Check it out!

http://colorvowelchart.org/index.php?option=com_content&view=article&id=46&Itemid=53

Practice minimal pairs in English

http://www.spokenskills.com/student-activities.cfm?section=studentpractice&practicepageID=1503

"Linguistics 101" reference

http://www.ielanguages.com/linguist.html