Other features of routers etc...
Some routers come with a built in USB printserver, this allows you to plug your printer into the router, not a machine on the network and then all machines can use the printer without needing the one with it attached to switched on.
http://www.ebuyer.com/customer/produ...duct_uid=52761
Other options enable you to buy wireless print servers (these often cater for Parallel and USB printers)
http://www.ebuyer.com/customer/produ...duct_uid=59957
or network cards for your printers (normally enterprise level laser printers), both will give the same benefit.
http://www.ebuyer.com/customer/produ...oduct_uid=8959
http://www.ebuyer.com/customer/produ...oduct_uid=8062
Additionally you can buy network attached storage devices. Such as the LinkStation Network Storage Center (HD-H120LAN) from Buffalo Technology which also has USB ports to act as additional HDD access and / or a Printer connection.
http://www.scan.co.uk/Products/Produ...oductID=127427