Yoga, yes.

Also, if you have an indoor rock climbing gym near you, you could start that. I'm having a blast with climbing, and for the first time in my life my arms aren't flabby, and when I flex my biceps something happens =) Climbing shoulders also look great in a bikini *big grin* ... and climbing definitely requires a strong core, although my core has never been so awesome ...

My general understanding of the way fat works is, you can't spot reduce. And getting muscle in your mid-section can push the fat out front, so it's more obvious. So the fat that starts to show first will probably be your hardest to get rid of =/