Hi, everyone, so now here's my little project: gsm-ussd.
"gsm-ussd" is a command to send USSD queries by GSM/UMTS modem. Everyone who owns a cell phone with a prepaid SIM card already knows at least one USSD code: "*100#". Entering this into your phone as a telephone number will display the current balance of your account - at least here in Germany. Such USSD queries are quickly done on your cell phone, but with your UMTS modem? Specifically the rebranded Huawei E160 I own? That's what gsm-ussd is for:
$ gsm-ussd '*100#'
You'll find that download here: gsm-ussd-0.1.0.tar.gz
Everything else is explained in the programs documentation.
Have fun and mail me your successes and problems!