Part of the fine print of Apple’s announcement yesterday of the new iMac G5 is that it no longer includes a built-in modem. Instead, you can buy a USB modem for $50. So let’s recap: way back when, you’d spend $200-$300 on an external modem, a big metal box with blinky lights that let you connect to local bulletin-board systems (BBSes) or the Internet. When Apple introduced the first iMac, the TV commercial boasted that you could connect to the Internet in two easy steps: plug in the power plug, and plug a phone cord into the built-in modem slot. Now, with broadband available to more homes, the modem (or “mo-DEM” as a New York Times editor once pronounced it to me) is again an external device. Only this time, it’s much smaller and has no blinky lights.