Select wifi channel in a crowded neighborhood

It seems that this will become a routine task for me.

Recently, I was suffering from serious network speed deterioration. I use an 802.11g wireless router to connect my computers and mobile phone to internet. As it turns out, there are about 24 wireless access points "visible" from my computer. Earlier, an year or so, I have easily selected channel 11 since most of my neighbors were using the default channel 6. Anyway, a quick check with NetStumbler reviled the horrible situation - all of my closest neighbors were using channel 11 - same as me...

Well, it was looking quite OK to move back to channel 6 since that channel looked least crowded and with the weakest signal. I did it.

Today, I have tried another tool inSSIDer that again reviled  a horrible situation. My neighbors were using routers that span over 2 channels, and the first program showed only one of them. After reconsideration I have moved to channel 4 - you can easily see the reason for that on the screen  snapshot  (the bold red curve is for my router). It could be particularly bad. Apparently one of my neighbors delivers stronger signal than my own router located in the same room as the computer... 

It is obvious that I will need to check the frequency spectra quite often... and inSSIDer will be the best tool for that.

Update: There is one more complication. Newer routers can also automatically select the best channel(s) that make my efforts useless. It seems that the easiest and better solution is to upgrade my old router, in other words, buy newer.