Problem? What Problem?

I have a problem.

Over my lunch break today, I decided to change the blade on my lawnmower.  I'm not one of those over-maintenancey guys who practically vacuums the lawn before I mow, so I routinely mow right over sticks, rocks, hidden toys... The blade was badly in need of being replace by something with much less chunks bitten out of it and much more actual blade. I haven't been cutting my grass lately, so much as I've been tearing it out in 20 inch swaths.

So I ignored the safety instructions about unplugging the spark plug, removing all the gas, and putting on a full suit of chain mail - I straddled the mower over two saw horses and did the job. You might be thinking this is where the problem comes in... it's not. Failure to capitulate to rubber room safety concerns may be a character flaw (or not), but it's not the problem I'm talking about.  Neither is ignoring rocks and sticks in the grass and putting neighborhood windows in peril. (And I'm really not heartless enough to mow over my kids' toys... usually.)

When I was finished, in the midst of putting everything away, I gathered up the packaging from the new blade to throw it away.  I threw my socket wrench back in the toolbox, along with the package of extra washers and spacers that I didn't need, put the mower and saw horses away, threw away the garbage... and this is where the problem is: I had to fight a very strong impulse to set aside the old mower blade.  I could hardly bring myself to throw it out. You never know when you might need an old mower blade, right?

Right?

Ok. Could somebody please tell me what possible use one could have for an old, rock-chinked mower blade?
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Just thought of something. Someday, I could could carve out a handle from those Christmas tree trunks I have laying around (two of them now), and make a sword! Excuse me now, I have to go retrieve something!