I've done this and so have countless others. After cursing repeatedly I found the plastic bag trick. After you rack out of the carboy, push one end of a plastic bag into the neck and get the plug intertwined in it. You should be able to pull the bag out with the plug. Not sure if the bag needs to be damp, but mine was when I did it from the water I used to clean out the carboy. As previously mentioned, there are some videos demonstrating it.
Also, I can't help but say "that's what she said" to theredben's comment:
"Remember that if it fit in it can come out."
Yes, I'm juvenile.