D-Link DWL-G730AP

From the press release:

Support for hotspot and router functions
The Pocket Wireless Router/Access Point is small in size but packed with features. The DWL-G730AP supports multiple operating modes, including: Access Point mode to create a wireless connection; router mode for sharing Internet connection; and Wireless Client mode for connecting to an existing wireless network. Ease of switching between these modes is provided by a 3-position switch located on the bottom of the device. In Access Point mode, the DWL-G730AP can be used to create a wireless network in a room that has a single Ethernet outlet. Multiple wireless clients can now connect to the network at the same time to share resources and files. In router mode, the DWL-G730AP can be used to organize shared Internet access, for example from a hotel room. The built-in DHCP server will automatically assign IP addresses, allowing all users in the room to connect to the Internet. Additionally, the DWL-G730AP supports VPN Pass-through and firewall features, including Network Address Translation (NAT) and MAC address filtering to protect your wireless network from malicious attacks.

Wireless connection without AC power
By switching to wireless client mode, the DWL-G730AP allows you to connect to an existing wireless network without installing drivers or additional software. For increased portability, the DWL-G730AP can be powered via USB when no power outlet is available.

Convenient for travel
The DWL-G730AP is significantly smaller than a mid-sized PDA, easy to pack and easy to travel with. It comes inside a travel case that also contains additional accessories including cables and a power adapter.