Upgrade #3: Adding Ports to a Portable PC
Adding a new port to a portable PC is particularly problematic. (My apologies for the alliteration!) You can't add a new port via internal card, so you're limited to going the USB route, or adding an expansion port on a PC Card. Either of these options is equally viable.
If you go the PC Card route, you need to be aware of which type of PC Card slot you have on your portable. Older portable PCs used a 16-bit PC Card slot, which isn't very versatile; you can't use it for USB, FireWire, or fast SCSI adapters. Most newer portables have 32-bit PC Card slots, which can handle just about anything you throw at them. (Check the specifications page of your PC's instruction manual to determine what type of PC Card slots you have.)
Some older PCs have trouble working with some external USB hubs; they might require constant rebooting to recognize the hub. If this happens to you, try plugging the hub into a different internal port, or try using a different brand of hub.