Thank you, someone, for your post asking "How do I..." in respect of the datalogger shield from...
That led me to visit the site... and I was delighted by what I found there. I would commend it to anyone who isn't quite as miserly as I am, and understands that their TIME is worth something.
Nuelectronics (with whom, just to be clear, I have no connection), offer...
(Skip down past the datalogger if it doesn't interest you... there's more!)
At only £12 (c. $18), a datalogging shield with Dallas 1-Wire support: NOT EVERY CHIP, but at least the DS18B20 ... and a RTC (DS1302) ... SD card interface for mass storage of sensor data ... ports for various sensor modules.
The sensors already available, each nicely mounted on a little PCB, and interconnect cable to sensor-ready socket on datalogger (or your own host devices) (See illustrations on site)...
For £2 (c.$3) each: Switch, thermistor, LDR, IR controller sensor (The IR sensor is intended for receiving signals from a TV remote control. They will sell you one which you can be SURE will "work" with the supplied software for £3... or hope that your existing controller will work, if perhaps with some software tweaking.)
For no more than £4.50 (d.$7) each: MQ-3 Alcohol gas sensor, DS18B20 (you can pay almost that for an unmounted chip!), DHT11 Temperature & Humidity Sensor Module, and buzzer output module.
(The DHT11 looks a cool little device, by the way. Not sure if it has already been discussed at this forum... I must go off and search old posts in a moment!)
So! I don't "know" that these guys are the best thing since sliced bread... but they look pretty good. I've placed my first order.
If you are in the US.... how hard can it be? You can pay with Paypal... they take care of all the nasty currency conversions, and the stuff nuelectronics sell is small, will go through the post easily. I buy things from the US for delivery in the UK frequently. Usually no hassle. Why should vice versa be hard? ("Security"? Bah.)