Yes, data breakpoints was mainly what I was thinking of. But I was thinking of assembly language breakpoints as well (Visual Studio doesn't store the addresses symbolically, or didn't seem to when I was trying it) - I've often found myself needing these too when trying to narrow down on some really ugly bug or other.

I've needed to do this on literally every single program I've ever worked on, and I've even missed them a few times in C#...