A couple of weeks ago I received my order from SparkFun with the HTU21, BMP180, and a small OLED display. I've gotten everything cobbled together, and a picture will be coming shortly.

I've also been experimenting with running everything at 1.8 volts. Everything seems to be working fine, but I still have the OLED and '328 running at 3.3 volts. This has also spun off a couple of other projects for supplying 1.8 volts from various sources. More on that in the near future.

Last week, I discovered that Bosch now has a single sensor that measures all three environmental parameters that I need. Nobody sells a breakout board for the BME280 yet, so I threw one together in Eagle and sent it off to OSHPark, and also ordered a few of the sensors from Mouser. I'll release the Eagle files once I've gotten the hardware in my hand and validate that it is correct.