VozMe is an utility you can add to your browser that reads any selected text in a web page aloud. You can select male or female voice. The installation of this utility (technically called bookmarklet) requires one step: drag the male or female link to your browser bookmark bar.
The most amazing thing is that this service has a gadget for iGoogle, even a plugin for WordPress so that our users can listen to our posts. It also includes an API for use in our websites and convert text into voice.