I've been using a Windows Mobile phone for a long time, and I've had a few gripes about it -- not the phone itself or the operating system, but generally the third-party software that people build, and specifically the user interfaces in these programs.

It's important to remember that you're building not only for a mobile device, but for a phone. As much as we don't want to admit it, we do use our phone when we're out and about, even driving. While everybody knows that we're not supposed to encourage people to use the phone when driving, the fact is, people do. Even in states with laws about driving and phones, you're typically allowed to use the phone in hands-free mode.

And that brings up how to make the software more usable. We're not talking about games here (I hope you're not playing Freecell you're driving!); rather, we're talking about things like launching an email program. For me, it's often a matter of while I'm sitting a traffic light (really, I swear), I'll grab the phone and click the button to start checking the email. Then when I'm at the next traffic light (really!), I'll glance at the phone and see if I have new mail.

Here's what this means for software:

• Make sure the buttons on the screen are BIG and clickable with my finger. Don't make me yank out the stylus. This is also true when I'm on a call and need to quickly switch to a different application, such as the contacts app, to give information to the person I'm talking to.
• Make the text big enough that I can glance at it. Or better yet, let me control how big the text is.
• If possible, include voice support.
• Make the application thread and process friendly. In other words, make it easy to switch between other applications, especially the phone app.