network manager does it for me clicking on the icon shows networks in
range.

played with wifi-radar it seems ok as well

I used wicd myself.....................

If your wireless adapter is supported by Ubuntu then the Network Application
will show all wireless networks within range. If it's not supported there
are alternatives, like Madwifi or Ndiswrapper. I'd tell you more about them
but I've never had to use them.

Please tell us which Wirelss Network Adapter are you using? Search the
Ubuntu forums to see if anyone else has got it working, and if so how.

Normally, the Network Manager will show no networks in range if the
wifi device isn't supported, I should look back again, but if he's
getting some networks listed but not others, I would theorize that it
could be Network Manager. That could be because I've had nothing but
issues with Network Manager though, I am bias.