Lima water is some potent shit!
[QUOTE=Exoticspirit;2907763]I should ask since it will be my first trip to Lima (and Cusco) -- is the tap water safe to drink for those of us coming from Canada / USA?[/QUOTE]You've got your answer already, but I'll add this: never take ice in your drink at any cheap restaurant (and that does include US chains restaurants as well).
I had the worst runs of my life (kid you not) from ice at a place in Larcomar because even after the guy specifically asked me if I wanted ice in my drink, I failed to take a hint and said yes. It took at least 2 months to clear up completely (and I'd been back at the States for a long time by then).