Wifi adapters: No luck out of the box with an Edimax EW-7811UN, Keebox W150NUIEEE, or dlink DWA-121. The latter two were recognized by my Beaglebone Green, but wouldn't associate with my access point. The Edimax showed up on my Beaglebone Black after an apt-get dist-upgrade, and associated once, but had tons of packet loss and never associated again.
Error message from the Keebox and D-Link usb wifi adapters:
# iwconfig wlan0 essid MyWifiName
Error for wireless request "Set ESSID" (8B1A) :
SET failed on device wlan0 ; Operation not permitted.
# ifconfig wlan0 up
Then "iwconfig wlan0 essid MyWifiName" works.
I tried this after connecting via ethernet and running apt-get update ; apt-get dist-upgrade, so I'm not sure if it'd work out of the box.