The Linksys WET54G Wireless Ethernet Bridge (compare prices) is shown above. It is only a bit larger than Linksys' wireless USB adapter.
True network bridge devices like the WET54G do not require device driver software installation in order to function, simplifying installation. Instead, network settings for the WET54G can be made through a browser-based administrative interface.
Like USB adapters, wireless Ethernet bridges can draw their power from the main cable connected to the host device. Ethernet bridges require a specialized Power over Ethernet (PoE) converter to make this work, however, whereas this functionality is automatic with USB. Without a PoE add-on, wireless Ethernet bridges need a separate power cord.
Wirelss Ethernet bridges commonly feature LED lights. The WET54G, for example, displays lights for power, Ethernet and Wi-Fi status.