Voki is a site that allows teachers and students to create a character and record a message for that character to say.
You can either choose to type the message and turn it into speech (see the example above by clicking on the picture) or use a microphone and record your own speech and have the character say that.
I have only had a quick play around with Voki this afternoon. I made the little character above and wrote a short text to speech welcome (which you will see if you click on it). If I had the premium version of weebly I am sure I would be able to embed the Voki so that it would just play by clicking the play button, however I only have the free weebly and so I have just had to link it. When you create the Voki you can choose the embedding link or the website link.
This is what the free version of Voki allows you to do. There is a premium paid version which looks pretty good - there is a video you can watch that shows you all about it.
However, the free one is also good.