If you want to practice pronunciation, this is the perfect site for you.

http://www2.research.att.com/~ttsweb/tts/demo.php

In this site, if you type any sentence you want to practice, you could listen the text in variety of pronunciation.

In this site, you can listen to any kinds of script you want. All you need to do is just type a sentence in the box and then click “speak” button. If you have some troubles in pronunciation, this site will be the most helpful site you can use. You can listen to the text in many kinds of voices; man or female, American or British. So whenever you have hard time pronouncing the sentence correctly, this is the site which you should visit.