We all gearswap, it's part of the nature of FFXI, I have two ideas, one easy to implement, the other difficult, that would substantially help the quality of gameplay for most FFXI players in my opinion.
1.) Limit visual gear updates to once every 10 seconds, and/or make it so that your target doesn't blink when they change gear. - This will stop the constant blinking people do, and heck, that can be a client-side setting so that if someone doesn't mind the blinking, they can keep it like it is, this should be easy to implement.
2.) Integrate gear changing into the new FFXI UI. I was really hoping you guys would do this in the first place. I select my macro named "Cure4", click "Precast" pull up a menu with every gear slot, slot all my fastcast equipment into it, and then click "Midcast", put all my "Magic Attack bonus" gear in that box, then click "Aftercast", and put all my "Refresh" and "Defensive" gear there.
Both of these things (and a lot more functionality you may or may not want to add) have already been created and work very well by third party programmers. Many, many players use them, but it would be nicer for everyone if it was built into the game itself.