Can two Base Stations exchange information on a wireless connection? I want to expand my wireless network with another Base Station that is more than 150 feet away. Will this work?

Unfortunately, AirPort Base Stations can not talk to each other wirelessly.

However, if two Base Stations are connected via Ethernet, then it is possible to have data from a client on Base Station A delivered to a client on Base Station B through the Ethernet connection.

With AirPort software 1.1 and greater it is possible to configure multiple Base Stations to create a single wireless network, otherwise known as active roaming. Active roaming is configured using the AirPort Admin Utility.

To set up active roaming, make sure that you:

• Connect all the Base Stations to the same subnet on your Ethernet network.
• Give the same network name and password to each Base Station.

• Set one base station to act as the DHCP server. (All other base stations should have Internet sharing turned off so they are only bridging.)
• Confirm that the Base Station set to act as the DHCP server assigns a range of real IP addresses. The private IP addresses used by Network Address Translation (NAT) cannot be used for roaming.
• Confirm that the Allow DHCP over Ethernet checkbox in the Network tab of the AirPort Admin Utility is selected.