How to use an USB 3G modem data connection with an Android phone (Galaxy Nexus)?
Officially: This is not possible, except for certain (older?) Archos tablets.

Inofficially: There's the Autopatcher project . It includes patches to enable 3G modems on wifi-only tablets (it may be possible to use those on phones too, but YMMV).

Autopatcher supports these Android firmware flavours:


some 3rd party firmwares (CyanogenMod, AOKP, ParanoidAndroid, PACman)
AOSP 2.3- > 4.3 (e.g., Google's Nexus line)
...and others


Not supported are original HTC, Samsung and other branded firmwares.