Over the last month or so, I have lost whole days of work due to internet connectivity issues. My wifi connection would drop unexplainedly. Pings would be 30ms to a remote host, then suddenly spike to 8s. Then my laptop would loose its connection with the router. Initially I spent time on the phone to my ISP trying to identify a network problem. Then, when I observed that pings to the router were just as bad, I realised it wasn't their doing. 

I had previously hacked a version of wifi-radar to add the channel to the list of nearby wireless networks, and with that I could see that I was not seeing interference from other wifi networks.

And sometimes, everything was just fine, and at others, connectivity would just drop out. Sometimes it my laptop was fine, and my wife's would just cease.

I did some browsing on 'wifi interference', and found a page talking about bluetooth. It commented that bluetooth uses channel hopping technology (please accept this as a layman's interpretation of the article).

I suddenly realised that the one thing that had changed recently was that I had had my BlackBerry Bold replaced as it had been crashing a lot. Switching off Bluetooth on it seemed to bring wifi back once more.

The thing that prompted this post occurred this morning when my wife said that her laptop was failing to connect. As soon as I switched off bluetooth, blam, it was connected and working fine.