Reusable Vacuum Cleaner Bags

I know Kenmore is in the money-making business, but why can't they offer a reusable vacuum cleaner bag? I don't know about you, but I'd be willing to pay a higher price for my vacuum if it came with a reusable bag. I've been able to find some reusable bags online, but I don't think they're compatible with Kenmore vacuums. The bag on our Kenmore vacuum currently needs changing, but before I head to Sears to buy another package of three, does anyone out there have any green ideas on reducing waste and saving money when it comes to replacing vacuum cleaner bags?