That little thing in the right hand corner of your windows operating system.

I live in a condo which has several APs all around the facility, but I always seem to be having connection problems. I've mentioned this numerous times in other topics and mentioned it to management. Lately I've noticed the speed changing frequently. It seems to jump between the following:
11.0Mbps
5.5Mbps
2.0Mbps
1.0Mbps
Kinda sucks when your using a 1.0Mbps connection and it tells you the signal strength is "very good." bah