Ekahau HeatMapper

What’s the best thing is [...]

Ekahau HeatMapper is pretty nice and simple Wi-Fi Coverage Mapping / Site Survey Tool.

Main features (Copy/Paste from EkaHau’s website):

Shows Wi-Fi coverage on a map
Locates all access points
Detects security settings and finds open networks
Designed for home and small office
Supports 802.11n, as well as a/b/g

What’s the best thing is that it doesn’t cost so much because it’s completely free (at least right now when I write this post).