That is exactly what my mom and grandpa told me to do with my first egg lol! They said I should blow it out, poor in glue to make a good support structure, and then paint it gold or bronze and mount it on a little plaque of some sort to commemorate the event! Too bad that I had already cracked and eaten it by the time they told me ... I just couldn't wait!
I have two of them in my kitchen that were layed about a year or so ago. I didn't blow them, I just let them evaporate. They're empty now from what I can tell. Just as light as a feather.
I opened one one time that was all white -- no yolk.
Pretty cute aren't they?!