TalkToMe is an app that can speak to you using a text-to-speech engine. There are three different ways in which the app can talk to you. The first mode, called Built-ins, lets you select a sentence starter, something like "Hello", "How are you?", and "My name is", and then you can type your own ending. The second mode is Famous Quotes. It includes seven quotes by different authors. You can select them from a drop-down menu that shows the first few words of the quote. When a quote is selected, you can read it in a text field below and can also add your own words anywhere in the quote. The last mode, called Write your own, lets you write whatever you want, and the application will read it from you. The voice used and the speech rate can be configured from the top of the screen. There are quite a few voices available, including some of the built-in voices in Mac OS X. There are voices with nice effects, like the Whisper voice or the Deranged voice.
In short, this is a fun application, but I don't see much use to it. You could use it to have the app read a text to you, but Mac OS X Lion can already do this for you.