Where do we get one?
I provided the link above but I will help you out on this one. If you follow the link to the openPicus main page click under buy. I chose the www.eikonsite.it because the Italian creators of the OpenPicus Flyport works at this company. They based their OpenPicus Flyport design and IDE software on the "ease of use" of their other Italian brothers, which made the first Arduino.
Where can we get the shield and how much does it cost?
There is no shield. Please read the web site information. It has 5 DI, 5 DO, I2C, SPI and 4 analog 10 bit inputs.
You can use this standalone or attach an Arduino to it to process your user application.
Note: In the standalone mode you provide small "C" code for the I/O. They have examples on the website.
The cost is in Euros (no VAT tax should be charged for US citizens) I bought the Flyport module and the nest for 49 + 19 Euro ~ 68 Euro or about $115.00 USD (includes secure shipping).
but the connection solutions often cost more than everything else in the project combined.
You also found this catch22 out. The problem of having an Arduino to take care of the TCP/IP stack communications and also the user application at the same time will cause more problems then it is worth. The OpenPicus Italian design team used a RTOS, a PIC24, ZeroG Wifi and the field proven TCP/IP stack that is rock solid.
I have looked at Asynclabs, Netduino plus and the FEZ WiFi solutions and they all fell way short in having a rock solid design.
If you ever wanted to be an IT expert (information technologies expert) then this OpenPicus Flyport will lead you into that profession. You will have to know the PC router basics to even put the Flyport module online to the world wide web. Not to worry, I started out being an IT moron and the knowlege I have gained from the Flyport was in-measurable. You have to do a lot of reading even though the OpenPicus IDE does most of the work for you. Not knowing the difference between AdHoc (peer to peer) and infrastructure (wifi access point) network connections will stop you dead in your tracks.
May I suggest the following links (along with the OpenPicus website information) to get you up to IT speed.
www.en.wikipedia.org/wiki/Internet_Protocol_Suite
www.support.microsoft.com/kb/169790
www.radmin.com/products/ipscanner/
www.chebucto.ns.ca/~rakerman/port-table.html
Please, before you buy thoroughly re-read the OpenPicus website information and download the free IDE and examine
the software. Also, look at their blogs and video.
Since I made every mistake, being an IT moron, on my Flyport project, I can help you achieve your goals.
You could also take a IT person out to lunch or find a computer geek to help you.