My husband races is bike, on the road and the dirt.  He spends at least an hour and a half riding every day (not counting the time spent commuting.)  What I want to know is what to DO with all those tires when they're no longer useful for him?  Got any ideas?

when looking for a bike, look to get a used one if possible, new bikes are pretty taxing on the environment in regards to the resources needed and the energy required for processing, they are pretty dirty to make, but clean to run

In the past year or so I've been commuting about 8 miles to work about twice each week, so I may not be putting quite as much wear on my tires as other commuters, but one difference may be that I have mountain bike tires with lots of fat "nubs" or whatever you call the treads.  My commute is partly on rougher country roads and up & down some bigger hills, so I actually find the mountain bike tires very useful.  If they slow me down a bit on smoother/flatter roads, I don't really notice it.

I'm a cyclist (or maybe I should I say was --- I keep hoping to ride more than I have in the last year or so). When I started riding seriously, mostly on crappy debris-strewn shoulders of suburban and exurban arteries, I would get flats with great regularity. Many per year. I switched to kevlar-reinforced tires for my hybrid bike and my flat tire ratio went down to one every several years. I suppose kevlar (the stuff of body armor and bulletproof vests) is pretty anti-ecological in its derivation and manufacture. But maybe there's an offsetting positive in slowing down the consumption cycle as dramatically as these much more durable tires have done for me. Some riders complain about a "harder" feel, but that never bothered me.

"I think because people ride their bike they automatically assume they are Earth-"friendlier" than others."

Sure, two sets of bike tires a year seems like a lot of petroleum products - but how much petrolem products are you NOT burning from a gas tank?  In rough numbers: driving a 25-MPG car 15,000 miles in a year consumes 3,600 pounds of gas and generates 12,000 pounds of carbon dioxide.  A few pounds for bike tires is a drop in the bucket.

Keep pedaling!

If you want to eliminate the wires in the tires you can still go back to the old silk sew-up tires which are still on my old ten-speed. They're old but still hold air and you can't beat em for weight and foldability for packing a spare.

Old tires make pretty cool chainstay protectors.  Cut the shape your need with a stout pair of scissors, and ziptie to your driveside chainstay.  

I average about one flat per bike every 18 months or so (which means three years between flats on any given tire) despite awful potholed streets strewn with debris. The Kevlar (or similar) belt really does help a lot. It costs a bit more per tire, but the tires themselves last for several years.

Used tires and tubes can sometimes be recycled at places that take car tires for recycling, often for less than $1 apiece. Look 'em up in the phone book -- and, while you're there, take a look around at just how much more waste those cars are generating!