Apple - A utility for tuning your WiFi network?

iStumbler

iStumbler is an application that shows nearby Wi-Fi networks along with lots of useful diagnostic information (such as signal strength and noise). It doesn't seem to have any built-in optimization tools, but it should get you started with some information.

List of features:

• Lists visible wireless networks with complete information.
• Inspector shows detailed information including a high-resolution graph, notes, extended properties and samples.
• Always displays the connected network, even if it's private.
• Graphically indicates network type and encryption status.
• Signal and noise graphed over time for the selected network.
• Connection monitor for connected network.

Wi-Fi menu extra

If you hold down ⌥ Option while clicking on the Wi-Fi menu item, you can see some more information about the Wi-Fi network you're connected to and others (hover over other networks to see information about them.)

Netspot

You can use netspot to basically create a 'map' of your location, and see network information around you. It will show you areas that network connectivity may suffer. You can then revisit the data points to possibly determine better locations for your router, or where the worst offending networks are to better decide which channels to use.

Apple has beefed up the Wireless Diagnostic tool to help perform the most important checks for most consumers:

• graph signal to noise ratio
• show TxRate negotiated between the chipset and base station
• suggest optimal channels
• perform a scan of open and visible base stations

You can also perform packet captures and collect some very nice logs in one file for analysis of conditions over time. I find a weekly check useful for problem sites or active work and also like to keep a diagnostic snapshot of the conditions when I place a new router in service. Also, the airport command line binary might be useful if you wanted to script some aspects of the data collection.