3. DD-WRT: To Super Charge Your Cheap Wireless Router
This isn't a program to install onto your computer; it is replacement firmware you can upload onto supported wireless routers.
DD-WRT gives you improved and new features, plus advanced ones that are usually available only in enterprise-class equipment.
Example include multiple SSIDs so you can offer varying encryption methods to the same or segregated networks and a built-in VPN client and server so you can securely connect offices together or offer connections to remote users.