Did a bunch of google searches, can't find anything
-What does the white button on the front of the mi424wr router do?
-What does the usb slot on the back of the mi424wr router do?
-What is the white ethernet-looking port on the back of the mi424wr for?
http://www.actiontec.com/support/product_details.php?pid=188&typ=all -- you can find manuals there. http://support.actiontec.com/doc_files/MI424WR_Rev._E&F_User_Manual_20.10.7_v1_GPL.pdf is latest for Rev. E.
Wi-Fi Protected Setup
WiFi Protected Setup (WPS) is an easier way to set up a wireless network. Instead of entering passwords or multiple keys on each wireless client (laptop, printer, external hard drive, etc.), the FiOS Router can create a wireless network that only requires the pressing of buttons (one on the FiOS Router, and one on the client [either built-in, or on a compatible wireless card]) to allow wireless clients to join the FiOS Router’s wireless network. Although the WPS button is included on the FiOS Router, WPS functionality will not be enabled until a future firmware release. The button is included so that WPS can be activated at a later date without having to physically change the FiOS Router. The GUI does not include the WPS option.
WAN Ethernet Port
The WAN Ethernet port connects the FiOS Router to the ISP using an Ethernet cable.
The USB port provides up to 5 VDC for attached devices (to charge a cell phone, for example). In the future, with a firmware release upgrade, the USB host functionality will be available for devices such as external storage and cameras.