X-Grip just released new mag sleeves allow the use of P30 magazines in the P2000 and the P2000SK.
The sleeves work great for use as the inserted magazine, not so great on reloads because the sleeves tend to slide around on the mag body.
I use the sleeves for extra capacity when I'm not CCW (nightstand, open carry in the desert, car gun, etc.).
Here's a pic of my nightstand P2000 with a X-Gripe sleeved P30 15 round magazine inserted.