Connectify is a useful application that turns a Windows 7 laptop into a wireless hotspot. Other laptops can then connect to it wirelessly and access the Internet through it. Instead of buying a wireless router, I have connected a Windows 7 laptop to the Internet and run Connectify on it. The other Ubuntu laptop at home accesses the Internet by connecting wirelessly to the network that Connectify creates. It all works like a charm with minimum tweaking!
The only problem I faced was that DNS was very flaky on the Ubuntu laptop. So, I configured it to use OpenDNS (instructions here) and everything works fine now! 
is there any apllication that act like Connectify but for ubuntu laptop?? thanks…
There does not seem to be any solution for Ubuntu that is as easy and painless as Connectify. But, this might be relevant to you: http://ubuntuforums.org/showthread.php?t=1324405
just install connectify version 1 back on your winndows 7 pc / laptop and your additional laptop with ubuntu will connect to the net no problem. the problem is with version 2 +… but with these versions a symbian phone with wifi can connect, but with version 1 a mobile device has difficulties connecting to the net through connectify… just thought id let you know.
regards george.