[polytap]

There are not, though I am building such a thing.

RF-equipped sensors (315 or 433 Mhz) transmitting to a GPRS or WiFi enabled hub would be best.

A fairly affordable foundation for that in Arduino-land would be the Fio or the LilyPad USB -- both of which have the LiPo charger.

[stcredzero]

There are not, though I am building such a thing.

Are you in Texas?

[polytap]

SoCal.

The professional/industrial environmental sensor market sucks.

Pretty much any sensor offering high precision is sold exclusively through authorized resellers that in turn hold the logged data captive and liberate it manually through what amount to expensive professional services contracts.

I'd like to smash that.

[stcredzero]

So how about low-power units in something like a NEMA23 form factor with some liPo batteries and a solar cell, with some rare earth magnets on the back? Put a cellular modem with GPS in it, and sell it through a website, where you can assign units to "flocks" or "clouds" and look at their data on a Google Earth style interface. So long as the bandwidth use is kept low enough, this can be done economically and within a power budget that would let these things run indefinitely.

Just having thermometers and microphones would enable a ton of uses. Like, how about in the energy industry, where FFT analysis of machinery sounds could be used for basic health monitors? You could sell a ton of those to the Energy Industry and they wouldn't bat an eye at $100 a unit. Just the ability to tell people to distribute them, then handle everything else from a website would be worth way more than $100 a unit for them. (The employment qualification bar for the more remote energy industry jobs is very low.)