Hi, i want 2 share my exp with this software. I have a Telsey UMTS/HSUPA with Fastweb provider (a MVNO hosted by H3G). The usb stick works thanks 2 telsey version of usb_modeswitch provided via the official support page, then you need to config umtsmon to use /dev/ttyUSB2 as PPP port. The only downside is that i wasn't able 2 find any suggestion about the configuration files for umtsmon on the official site, i found it on a personal blog searching on google. After configured, umtsmon starts from the Application menu (Gnome) putting "gksu" before the command to lauch it with root permission.
Hope it could b helpful :)