If you're using Windows, then you should be able to create an Ad-hoc network using any wireless adapter.
Here are the instructions on how to create one (from Microsoft's site: http://windows.microsoft.com/en-us/windows/set-computer-to-computer-adhoc-network#1TC=windows-7)
1. Open Network and Sharing Center by clicking the Start button Picture of the Start button, and then clicking Control Panel. In the search box, type network, and then click Network and Sharing Center.
2. Click Set up a new connection or network.
3. Click Set up a wireless ad hoc (computer-to-computer) network, click Next, and then follow the steps in the wizard.