By sticking with mobile Web 2.0 devices, that universe got a lot smaller. That range of sizes is still bigger than it should be, but I'm confident that the iPhone's 320-by-480-pixel screen will set the bar for the rest of the market, in a year or two, we'll see most devices either at that size or at a 240-pixel width, as many Palm, Symbian and Windows Mobile devices still use.

Fortunately, Kennedy had designed his monitors to be compact, so it was trivial for him to adjust their size to fit the 240-pixel width I decided would be our minimum. That left precious little space for the "skin" that wraps his monitors, presenting a real challenge to our designer. Ultimately, I asked him to design it to look good at 320-pixel width but to work in a collapsed form at 240 pixels. My bet is simple: The world will coalesce at the 320-pixel width in the next two years, so the 240-pixel devices are soon to be our legacy and should not overly confine where we want to be.

The designer had to make sure the UI fit in the small space, something I tried to anticipate in the prototype stage with a very simple interface that would reside in that skin. We did not want to repeat the mistakes of many early Windows Mobile apps, which tried to shrink full screens into postage-stamp-sized spaces. So the interface is minimalist: a simple pull-down menu lets you move from one widget to another (it also saves users from having to move among four separate bookmarks on their mobile device to see the different monitor views). We took another page from the iPhone experience and aimed for a simple interface.

Because the mobile "app" is really a miniature Web page, I could also avoid having to add a sign-in area in the skin. Instead, the e-mail that generates the link for you to bookmark on your mobile device simply appends your unique ID using a simple JavaScript snippet, so the sign-in is embedded into the URL. Because neither the ID nor the displayed data identifies whose systems' performance data is being displayed, we were all confident that this approach would not cause privacy concerns.

And pure elegance is the only way to describe the simple extension that Apple provides to HTML CSS to let users easily add a Web page as an app to their iPhone's home screen -- it's an easy way to get viral distribution. Yes, I know it's essentially the same concept as an ICO file for a Web page to put an icon in the Web address in a browser. That's elegant too -- and Apple doesn't make you use a weird file format.

Desktop widgets: AIR to the rescue
So mobile was easy, once we decided on a minimum standard based on the popular leading-edge devices. But the other type of widget -- the desktop widget -- was a bit trickier.

I wanted to offer a desktop widget, something you could leave running on your computer even if you weren't in your browser. After all, an admin is going to be doing lots of stuff on his compute, and keeping a browser window open all day for these performance monitors wasn't a realistic goal. But leaving a small widget running on the desktop -- that's already been proven effective in the BI world.

But how to do this in a lightweight way?