Do you love the "ding-ding" sound of a service station bell, triggered by driving over a pneumatic hose. Milton Alberstadt of Houston, Texas, certainly does--he makes his living selling them at Milton's Bells.
But he's also a geek, so he has rigged an interface on his PC that is triggered by incoming e-mail rules in Outlook to ring one of his bells. The "merger of the Internet and petrolania," he says.
Milton sells all the distinctly analog parts you need to do the same (bells, hose, y-splitters, and so on.) but you'll have to cajole him by e-mail to get a copy of the little .bat file he wrote to make it all work. Make his bell ring and we bet he'll share it.