What does ttyUSB mean? Sometimes, the embedded microcontroller does not come with a hardware USB interface. While it is possible to use a software-only USB stack, the additional constraints put onto the CPU and the usually small storage size often lead board designers to include a dedicated UART to USB bridge.
Because of a busy weekend I didn't really follow up other than via emails and this still hasn't been resolved. The consistent word from them was that porting a number sometimes takes 24 to 48 hours.. I spoke to a rep by phone today who promised it would be done within 2 to 4 hours.. It wasn't.
Thanks rolandh, I went to T-Mobile and spent $10 to have my phone number port out in 5 minutes. One suggestion given your short timeline before your trip. You could port your number to a number-parking service such as RingTo, then forward your number from RingTo to your Cricket phone.