When I was a PhD student, my papers almost always had author order alphabetical. I later learned that other fields cared about "first author". At first, I couldn't believe it - it's so obviously ripe for abuse. But I found out it's true - and abused.

I'm in a more senor position now and I still prefer alphabetic order. Having more power than coauthors has somewhat softened my stance though, as my preferences shouldn't be forced upon underlings.

But it is still baffling that anyone (let alone scientists) puts any stock in author order.