I recently came across a useful application called Virtual Router over at CodePlex. It creates a Wifi Hot Spot on any computer running Windows 7 (all versions except Starter) or Windows Server 2008 R2. I installed it on my Acer Aspire One Netbook and gave it a try.
Virtual Router worked great. I was able to connect to it immediately. I can see using this when at remote locations with a couple of wifi enabled smart phones. Here's a quote from the project page:
Virtual Router turns any Windows 7 or Windows 2008 R2 Computer into a Wifi Hot Spot using Windows 7's Wireless Hosted Network (Virtual Wifi) technology.
The Wireless Network create/shared with Virtual Router uses WPA2 Encryption, and there is not way to turn off that encryption. This is actually a feature of the Wireless Hosted Network API's built into Windows 7 and 2008 R2 to ensure the best security possible.
You can give your "virtual" wireless network any name you want, and also set the password to anything. Just make sure the password is at least 8 characters.
If you are running Windows 7 (all versions except Starter) or Windows Server 2008 R2 and have both wired and wireless network adapters, you should give this application a try. It is available for download from the Virtual Router project at CodePlex.