I have the "4GLTE" LG VL600 usb modem from Verizon on a consumer
data-only $50/month plan and it gives my Windows 7 laptop
a v6 address on both 3G and "4G" connections. I noticed it
recently when I was logged into the ARIN website since their
site puts a banner across the top when you're accessing via
ipv6; then I tried other sites to confirm it was working.