Apple has offered a software base station feature in its client software for nearly five years; PCTel now brings the same ease to Windows with Segue SoftAP: Under Windows XP, you can set up an ad hoc Wi-Fi network and then link that via Internet sharing to bridge an Ethernet, modem, or other connection to users connecting over Wi-Fi. But it's multiple steps and not really the same thing as creating a full software base station.
Segue SoftAP from PCTel will cost $19.95 when it goes on sale to individuals this month, and offers all of the security and networking features needed for a robust, computer client-based offering. Of course, contrast this offering versus a $30 to $80 dedicated access point, and it might seem like a less desirable offering unless you're a mobile or portable computer user who needs to set up Wi-Fi hotspots on an ad hoc basis. [link via Steve Stroh]