CM1000

   My cable-TV modem experience is minimal, but...

> Can I use my iPhone to setup my modem

   Visit http://netgear.com/support , put in your model number, and look
for Documentation.  Get the User Manual.  Read.  Look for "Install Your
Cable Modem and Connect It to a Computer".  Clearly, the instructions
suggest using a wired connection from a computer directly to the modem.

   If you read further, down to "Connect Your Cable Modem to a Router
After Installation and Activation", you may see:

      During the installation and activation, you must connect the cable
      modem directly to a computer. After installation and activation,
      you can connect the cable modem to a router.

   You could try connecting a wireless router to the modem before "the
installation and activation" are complete, and see what (if anything)
you can do at "http://192.168.100.1".

   Alternatively, obtain (borrow/buy/rent/steal/...) a computer with an
Ethernet interface.