Just about everything that I want to share across my network connects via USB. Generally, if I want to share my printer or an external HDD I just connect it to my PC and then allow other computers to share it via my computer. That never seems to work for too long though because every other time someone tries to print they get error messages and you have to remember to leave the computer the devices are physically connected to on at all times.
IOGEAR has an interesting new four-port USB wireless sharing station that will make it easy to connect to your peripherals even if you turn your computer off. The four-port USB hub is called the Wireless 4-Port sharing Station and is part number GUWIP204. The device can be used to connect anything that has a USB cable on your WiFi network.
It will work with printers, external HDDs, memory card readers, webcams, speakers, and just about anything else you can think of. The device also supports USB 2.0 hub extension. The hub is available right now for $99.95.