Should I chang to a switch??

Hello, here’s my question…
Right now I have a cable modem going into a router, which in turn runs to a hub. There are 4 computers connected to the hub. For the most part, the connections are just used for the internet, but occasionally we use each other’s hard drives to back things up while reformatting or trying out new OSs (ie linux). My current hub is a 10 mbps hub…my question is…should I upgrade to a 10/100 hub or spend a few extra bucks and get a switch??? Thanks for the help.