Words within words

What is it called when you use a word in a word, i.e. You are "Sand"sational?

Not very punny?

L

Some other possiblities are portmanteau, blend, and compound.

Sandwich words are when the word is inserted in the middle. Fan(flipping)tastic.

The recent fad for capitalizing one of the internal letters of a name (eBooks, iPod, etc.) has been called an "embedded capital"; and so, I suppose, these things could similarly be called embedded words.