USB modem with Linux?

Hello I am using SuseBlinux with hardware speech synth and Braille display on com1 and 2. I only have a winmodem which uses virtual comport 4 and will therefore not work with Linux. I only have two physical comm ports on my machine. Is there any way around this? I wonder if any USB modems are supported in Linux - specifics would be helpful? I do not think software speech is fully developed yet and the Apollo2 is very responsive. Any help welcomed please. Thanks.