Does android, specifically the HTC Incredible, support headphone volume buttons? Coming from the IPhone, I love being able to control my phone from my wired 3 button headphones.  Center clicking to start/stop music or answer calls and using the 2 volume buttons to adjust the volume without pulling the phone out of my pocket.

I've tried different 3 button headphones with my HTC Incredible and can answer calls and pause and play audio with the center button, but I've never been able to change the volume from my headphones buttons.

Are volume adjustments via headphones supported in the HTC Incredible?  Am I just using the wrong headphones?
Definitely supported by Android, and I'd be incredibly surprised if the Incredible didn't support volume control. 

I had no problem using the volume control buttons in the headset I bought for my G1. I bought mine on eBay for $7, it has no branding but was marketed as explicitly for the G1. It uses the USB plug, not the 3.5mm plug. 

You might need a USB headset.

There is something specific about apple's 3.5mm jacks that doesn't play well with non-apple devices. Something about the placement of the insulating plastic bands. It is described in the answer to: Why can&#39;t I use my iPhone Headphones with my HTC Thunderbolt? 

So it wouldn't surprise me if a headset from your iphone with a 3.5mm jack would not work on your Incredible. But if you buy a headset manufactured for the incredible (Ebay and Amazon appear to have plenty) and the volume controls still don't work, the problem is probably your device.