Try Digital Walker, in malls. It sells accessories, including bags and sleeves. Power Mac/Digital Hub and other Mac centers may have them too. Look at other brands as well. Travel Club and Bratpack both sell backpacks such as Eastpack, Northface, High Sierra, Jansport and there are models specifically suited for laptops.

Golla products can be purchased at the following locations in the Philippines.

TELECOM SPECIALISTS:
Best Mobile
Unicell
Xsite Mobile

ELECTRONIC STORES:
A Shop Apple Stores
Apple Center
BSD
Clipper
Fully Booked
Gadgets in Style
Globotel
Hello
I-Gig
I-Studio
Powermac Apple Stores
Powertel
Switch Apple Stores
Vertex

OTHERS:
Bratpack
Republik Clothing Store
Island Souvenir
Sanborns
Travel Club