WirelessConnectionInfo is a tiny portable tool which displays various statistics on your wireless network.
This can immediately be very useful. At a glance you'll see details like your network SSID, PHY Type (802.11n, say), signal quality, security algorithm, channel and more.
The report isn't just a static text file, either. Check stats like "Transmitted Frame Count", failed/ retry counts and more and you'll see them updated in real time.
As usual with NirSoft tools, there are options to manually save a text report containing this data.
You can also automate the process with various command line options, for example enabling you to run a scheduled task and save the current state of your network at regular intervals.
WirelessConnectionInfo is an easy way to find some useful wifi stats. It's poor as a real-time viewer of network activity - you can't choose what you want to see, there's lots of horizontal scrolling to view everything, you can't turn monitoring on or off - but it's hard to expect more from a single executable under 100KB in size.