disable volume buttons Problem at hand: I keep pressing volume button on my Nexus S when it is in my pocket. Most notably when playing music. More often than not it results in increasing volume, which is incredibly irritating.
Had exactly the same issue with Nexus One.

Desired solution: A tweak/app that simply disables volume button when the screen is off (or locked?)

I looked through the android market and found a few half baked solutions... I don't really need a widget or a prompt to revert volume change or a being have to run an extra app when I actually want to change volume.
I had this problem a LOT with my Thunderbolt. The solution I went with was to buy a low-profile TPU case for it and I've LOVED this solution. Not exactly what you're asking for but it might be something to consider. I chose a $5 "S-Line" case from eBay that lots of people sell. It's great and adds a lot of protection at little cost and is as low-profile as you can get a case to be imho.