No serial ports on my laptop, looking to convert a USB port to a serial port, I've found the adapter already. the million dollar question is : can I use this one serial port for 2 different perferial devices (GPS & cell phone- not at the same time)or will I have to reload the software for each device each time I want to switch to the other device?

Most computers allow for four serial ports, but only two devices. If you have a serial modem or mouse then only one of the other devices at a time will work. I've had three serial devices installed at the same time (digital camera, drawing pad and modem) and sooner or later one or the other starts to conflict with one or the other. I've tried screwing around with the IRQ's and the I/O settings, but I always end up uninstalling either the camera or the drawing pad to get the other one to work. Part of my problem was the camera wasn't plug-and-play. If both of your devices are plug-and-play you may have better luck than I did.