Having finished my work on residential gateways, I am more convinced than ever there is a huge opportunity here for someone. (Illustration from Parc.com.)

It won't be the phone company. Consumers don't trust the telcos and there is no law requiring that the ISP serving a gateway must be the one providing your local access service.

It may not be a router company either. There are big problems with present wireless LANs. Their reach is spotty, and boosting their signal only means the neighbors can get on your network.

The big opportunity lies in the middle. The big unmet need is for security.

So let me offer you a "black box." Call it a firewall, or a gateway, or make up a name for it. It's based on PDA technology, its batteries recharged from the wall through some AAs (and software to maximize the life of those AAs by recharging only when necessary). It never turns off.

Its firmware will automatically protect both your Internet connections and your internal LAN. This means if you have a wireless LAN, it will mandate proper security precautions -- separate sign-ins for each user and device, encryption of all traffic. On the Internet side it will provide firewall services, anti-spam and anti-malware protection, and an anonymizer -- the best firewalls are always external to your PC and use hardware anyway.

While right now you're buying yet-another box, you're actually replacing a whole lot of things with something better. You don't have to worry about updating your anti-virals, your anti-spam blacklists, or implementing proper wireless LAN securitiy. The hardware comes with a one-year subscription to an update service, which works in the background, starting from when you register the thing. (And with things like Google's Autofill, that should be pretty easy too.)

Of course, you could add a modem and have a gateway. You could add bunny ears antennae and have a wireless LAN router. Obviously you're going to want several models, and you're going to want to license everything at reasonable prices.

Best of all, this box must be expandable. It should have PCMCIA slots, into which you can plug firmware modules providing support for wireless LAN applications. Things like medical applications, or home automation applications, all running on Zigbee-based sensors that can be on your person, on your pet, embedded in your lawn, on your house -- wherever.

The box runs on an embedded version of Windows, of Linux, or of the Macintosh operating system. (If it's a Mac we call it iHome.) It provides real value for money as a security device. It's cheap to make, easy to update remotely. And since it's expandable there's value for the future, a platform for Always-On applications and application development.

Get to work on it.