my neighbor from down the block... check out his home made panniers!

Bret at Bike to Work Day

Bret with his DIY bicycle panniers
Bret used some kitty litter containers 
simply bolted them onto the rack
WATER TIGHT! 
seem to be holding up!

sure... not exactly as light as canvas or nylon
and no... not aerodynamic 
but very useful
and inexpensive!