How to expand 50 cent's brand

There was a time, believe it or not, when 50 Cent was just a rapper.

Sure, the multiplatinum-selling emcee has a new album, "Street King Immortal," due out this month. But that album is but one small part of the Curtis Jackson Empire, which already includes publishing (he appears at the Fifth Ave. Barnes & Noble tomorrow to talk about his new book, "Formula 50"), acting, fashion (G-Unit Sportswear) and beverages (SK Energy Shots).

Even with all of those products, though, it feels like 50 Cent is leaving money on the table. What else could the mogul hawk?

amNewYork has some ideas for the rap superstar to consider ...