You can use bluestacks. It's a android emulator that basically lets you run android apps on your pc. Download instagram and sign up.
Ok guys, so I'm hearing that Bluestacks sucks... anything else? Does anybody know of any chrome plug-ins?
I use Igerslike to create accounts w/ Google voice numbers. Although I hear that igers also sells #'s but never tested that out. If you take all the right precautions you should be good