For you guys want to use this ( best application ever ) cool application from iPhone, don’t waste your time to configure manually or with wicd, wifi-radar or such. Your best bet is to use networkmanager. Most of modern ( all ?! ) distro have this in packages manager.
For debian/ubuntu :
For debian/ubuntu :
aptitude install network-manager network-manager-kde
( last package is for kde, but there’s interfaces to xfce4, gnome… too )
That use the simpleness of wifi stuff on Window$ on your Linux boxes.
Enjoy !
Edit:for people using Android phones, since version 2.2 Froyo, it’s implemented by default ( see tethering in your network settings )