Why a hub, tho? Switches are faster and cost about the same nowadays. That, and you'd be hard-pressed to find a hub that's anything but 4 ports.
In case you're wondering why, a hub splits the maximum bandwidth up by how many connections it has. So, if you have a 100MBit connection running through all the lines hooked to the hub, and there were two connections, you'd actually only get 50MBits (Max bandwidth divided by the amount of connections, or in this case, 100/2=50). That's why you won't see more than 4 ports on an ethernet hub- 100MBits divided by 4 is a crawling 25MBits. Any slower, and you're dealing with 10BaseTx, which is only 10MBits a second.
EDIT: Oh, yes, let me clear up a possible confusion- I suggest switches over hubs because they don't split the bandwidth. You get the maximum bandwidth across all connections, regardless of how many there are. A 5-port switch goes as fast as a 100-port switch.