We're totally nuts about our Gmail here at Download Squad. I've used my Gmail for all sorts of interesting things over the last 2 and a half years. I'll give a tip of my geek-hat to Steve Rubel though, and his article, "Turn Gmail into Your Personal Nerve Center."

Among Rubel's tips, using Gmail as a personal database -- something I do, but not quite as extensively as Steve --, blogging from Gmail, and using integrated GTalk to feed IMified --making up for Gmail's glaring lack of communication skills with Google Calendar (or any other).