What short range wireless is good for hundreds of nodes?

[Ichan]

Bluetooth, wifi, zigbee, miwi, cellular or what?

Before our buddy Solutions shouting, that is for silent bidding device.

-ichan

[bigtoy]

Not bluetooth or WiFi due to "number of nodes" restrictions.
Not cellular due to cost.
Zigbee certainly supports large numbers of nodes.

[Gallymimu]

Zigbee and zwave are OK if you don't need TRUE mesh (ie must have powered nodes to collect data from battery powered nodes throughout network).

I'd consider looking at Contiki  it's  an open source TRUE mesh.

[PICker]

Have a look to some industrial and proprietary solutions from TI:
http://www.ti.com/lsds/ti/wireless_connectivity/overview.page

[Gallymimu]

Zigbee and zwave are OK if you don't need TRUE mesh (ie must have powered nodes to collect data from battery powered nodes throughout network).

I'd consider looking at Contiki  it's  an open source TRUE mesh.

Link for Contiki http://contiki.sourceforge.net/docs/2.6/index.html

[karri]

I do not know, if it is still current. I use IQRF TR modules from Microrisc:
http://iqrf.org/
I have published several articles with constructions on this website:
http://doitwireless.com/

It is not so cheap as some solution with (for example) Hope RF, but it is ready to use, and you do not have to study tons of docs. You can control new from coordinator site via USART or SPI, or you can write your own control application to the coordinator. Check some my arcicles...

[PICker]

I think that ESP8266 is the best and cheap solution Today:
https://en.wikipedia.org/wiki/ESP8266