Any way you can make the code more legible (maintainable) is a good thing. I'm not saying that the grep usage is a bad thing, as I don't know enough Perl idioms to recognize whether it is or not. But the do { ... } foreach @list; is pretty darned easy to read and recognize what the code does.

Someone (Kernighan?) once said something to the effect of: Debugging is harder than coding. If you write the cleverest code you can, then by definition, you can't debug it.

If only I could learn to live by that motto ... my life would be a lot simpler.

--roboticus