Lockscreen on capacitive touchscreen? My phone (SE Xperia X8) has a capacitive touchscreen, which, I'm told that only reacts to fingers.
So does it have a point to have lockscreen enabled?
I use Cyanogenmod so I can easily disable it.
You're almost right. 


  Capacitive screens can detect anything that's conductive or has a dielectric difference to air.  


Here's a good Wikipedia article about this.  

If you carry your phone in a pocket, you can easily activate the screen without noticing it. Try this:
Put some cloth (eg. Jeans) between your hand and the screen, now if you press it hard enough the touch will register.

If a button is accidentally pressed while you slip it into your pocket and you have lockscreen disabled, it's that much easier for your butt to dial someone. And you don't want that do you?