If you’ve been amused by the lengths people go through to speak to a serial device these days. [timmeh] just took the cake. He build his own frikkin’ tiny RS-232 to USB interface with the diminutive SIL CP2101. The package on it is QFN-28 (If PLCC is Darth Vader, QFN-28 is his mean little brother.) That said, if you prefer to work with stuff that talks TTL or RS-232, this could be a handy add-on to pop a USB port on your project. (Oh, look, they have samples…) Sure, we’ve beaten the serial connections to death, but they’re so handy we just can’t resist. It may be a decent way to add a serial port to your laptop. (Picture this: dell’s bluetooth cards are usb devices – you could add one of these without even voiding your warranty.)

[Alan] sent me his simple rs-232 controlled power outlet. He built it to turn on his laser printer when a print job appeares in the queue. The relay is directly controlled by the DTR line on the serial port. Lots of espresso machine PID conversions use them to run boilers, so he could have avoided the extra mechanical relay. [I can't pick on him too much, my old laserwriter is on all the time.]

He tied it together with some perl to turn on the printer and get the print job going once it’s had enough time to initialize.