Nicole Kidman Spins into shape

Nicole Kidman is pinning her wheels -- her bike wheels -- during her new-ish pregnancy.

Kidman was spotted recently in a Spinning class in Santa Monica, doing her exercise thing and staying in shape. Her baby bump was very apparent, say the sources who saw this mommy-to-be.

The soundtrack playing while Kidman pedaled away? Songs by Mary J. Blige, Bon Jovi, and Culture Club rocked the place. Her favorite, though, said a fellow gym-goer: songs by hubby Keith Urban.