WiFi signal goes from zero to full back to zero

Jul 14, 2008
Lately, I've noticed that my wifi signal strength is all over the place, from full to zero/one bar and back, all without me moving or doing anything. This happens with both my home and workplace wireless routers, where in the past I've had no such issues with wifi signal strength.

I'm running 2.2.1 on a stock 16 gb 3g, any ideas/suggestions? Frankly, I'm not sure if this was happening before I upgraded to 2.2.1

Thanks in advance!