With inSSIDer you can inspect your Wi-Fi and surrounding networks, scan and filter hundreds of nearby access points, troubleshoot competing access points and clogged Wi-Fi channels and more.

You can:

Inspect your Wi-Fi and surrounding networks

Scan and filter hundreds of nearby access points

Troubleshoot competing access points and clogged Wi-Fi channels

Highlight access points for areas with high Wi-Fi concentration

Track the strength of received signals in dBm over time

Sort results by MAC Address, SSID, Channel, RSSI, Time Last Seen

Export Wi-Fi and GPS data to a KML file in Google Earth

Technical:

Uses your current wireless card and connection software

Works with Windows XP, Vista, and 7 (32 and 64 bit)

Compatible with most GPS devices (NMEA v2.3 +)

Limitations: Requires .Net Framework 3.5+ installed.