A range of cheap and cheerful flats from Cotton On
Currently $5 a pair with free delivery
Red
http://shop.cottonon.com/shop/product/ivy-flat-crimson/
Blue
http://shop.cottonon.com/shop/product/ivy-flat-cobalt-micro/
Black
http://shop.cottonon.com/shop/product/ivy-flat-black-micro/
Leopard
http://shop.cottonon.com/shop/product/ivy-flat-leopard-micro…
Zebra
http://shop.cottonon.com/shop/product/ivy-flat-zebra/
Green
http://shop.cottonon.com/shop/product/ivy-flat-porcelain-gre…
Fold them up and leave them at work when you need a rest from your heels
Just bought two pairs and intending to keep a set at work, like you said. Great idea :)