I also love QR Voice, but I was hoping I could find something that I could use that would allow me more than 100 characters. I found one, but it was blocked here so I was on the look out for something that would work. I stumbled across a site that would allow me to record my voice for as long as I need to and when you save it gives you a link. I think took that link and put it into a QR code maker and BAM..I got what I wanted.
Here is the site I use: http://vocaroo.com/
Here are some great resources for QR codes in the classroom: