The function will take a string and create an MP3 of the string being spoken and named after the first 15 characters of the string:

t2s() { wget -q -U Mozilla -O $(tr ' ' _ <<< "$1"| cut -b 1-15).mp3 "http://translate.google.com/translate_tts?ie=UTF-8&tl=en&q=$(tr ' ' + <<< "$1")"; }  
t2s "Hello reader!"  

Produces the following:

ls -lh Hello_reader\!.mp3  
-rw-r--r--  1 westlund  staff   4.5K Nov  3 13:42 Hello_reader!.mp3

Pretty slick. One thing to watch out for is that Google can flag your requests and unusual, if the alias is failing try launching the URL in your browser and see if it brings up a CAPTCHA.