While it has been possible to use profiles in the Little Snitch traffic monitoring utility to create a set of rules that limit connections, you still had to remember to switch to that profile manually. With Little Snitch 3.1, Objective Development has added a new Automatic Profile Switching capability that enables you to assign a network (such as your home Wi-Fi network or a coffee shop hotspot) to a specific profile. When you first connect to a network, an alert window pops up to ask which profile you want to assign to the network. You can also choose to do nothing or configure a default profile that will be used for all unknown networks. No network traffic is allowed while the alert window is open to prevent email and file synchronization accounts from sending and receiving data in unwanted situations. Other changes in Little Snitch 3.1 include an improved Restore Factory Defaults feature, a bug fix for a rare issue that could cause a kernel panic, and an updated help section covering the addition of Automatic Profile Switching. ($34.95 new, free update, 13.2 MB, release notes)
Viewing Wi-Fi Details in Snow Leopard
In Snow Leopard, hold down the Option key before clicking the AirPort menu. Doing so reveals additional technical details including which standards, speeds, and frequencies you're using to connect, as well as what's in use by other networks. With the Option key held down and with a network already joined, the AirPort menu reveals seven pieces of information: the PHY Mode, the MAC (Media Access Control) address, the channel and band in use, the security method that's in use, the RSSI (Received Signal Strength Indication) measurement, the transmit rate, and the MCS Index. In Leopard, some, but not all, of these details are revealed by Option-clicking the AirPort menu.