Ornithopter is another card, like Howling Mine and Lightning Bolt, that has seen many reprintings over the years of Magic. Originally appearing in the Antiquities set, I'm honestly not sure what applications the card had aside from being a cheap chump blocker. There could be some crazy deck tech from back in the day I've never been privy to, but off the top of my head I can't think of anything significant.
Eventually, though, with cards being able to effectively make Ornithopter more useful, whether via enchantments (like Tempered Steel of Scars of Mirrodin), equipment, spells, etc, the card was able to make its way into competitive play (especially in the Modern format). Again, this may have already existed before my time, but I know I never played with it before those specific additions to the card pool.
I used Ornithopter for a while in artifact themed decks where these enhancements were readily available. Even if the necessary cards weren't prepped, it could still be thrown out as a chump blocker and/or used to help trigger mechanics like Metalcraft (where you need three or more artifacts to gain its effect), which its 0 casting cost is really ideal for.
This copy is a Magic 2010 foil. Not exactly worth much, but I remember being excited to have a foil Ornithopter in my collection. It's the little things, I guess...
Have you ever played with Ornithopter? If so, which decks do you use it in? Have you ever played with it competitively? What cards have you used to enhance Ornithopter?