Elon Musk, owner of a $100 million real-estate portfolio, just tweeted that he will sell all his belongings and 'own no house.' Take a look at some of the mansions he'll have to offload to make that happen.

· Elon Musk vowed to sell "almost all physical possessions" including his homes in a tweet Friday.
· Months before promising to fully liquidate his real-estate portfolio, the Tesla CEO reportedly sold a Brentwood, California, mansion for almost $4 million in late August.
· Musk owns at least seven houses worth a combined...