Although the picture IBM e-mail thing at Epcot's Innovations is a one-way deal.
I found that in the space for the name of the person you are sending it to, you can type as much information as you want to.
Just in case you wanted to send a one way message. I just type their name,then comma, then type away.
And I haven't used those internet kiosks before, but I'm sure any castmember could help you.
Disney Quest also has an internet cafe.
Most resorts may have a business office that charge for internet use, too.
Have fun.