The new "in" thing seems to be having a scent of your own, and far be it from Christina Aguilera to buck that trend. The pop tart announced on her website that she's inked a deal to develop a self-inspired fragrance line, just like Britney Spears, Hilary Duff, J.Lo, Paris Hilton have done. (Both Gwen Stefani and Kate Moss are also in the works to create their own perfume lines.) "I love trying new things in my music and in fashion," Christina said on her website. "To have a perfume of my own is the beginning of an exciting adventure." Hmm, we don't know about buying perfume from a dirrty girl…