Like most business people, time is my most valuable resource. I do everything I can to optimize the use of my time, reduce wasted time and recruit help from others who can positively impact my time utilization.

That means taking advantage of dead time -- those small time slots that otherwise get wasted, such as travel time. An associate of mine calls this "windshield time."

Windshield time is difficult time to use -- you can't type out a memo, create an artistic strategy on paper or give yourself a full body workout. It's just too tough -- OK, impossible -- to do. But you can think -- and, in some states, you can talk on your cell phone.

Some people like to use wireless "hands-free" headsets so they can keep their hands on their steering wheel instead of holding their telephones. That's a wise move -- although studies have shown that accidents often are caused by the mere distraction of what you're talking about, not just the lack of hands on the steering wheel. Those studies suggest that listening to the radio and talking to the passengers in your car are just as distracting and can cause accidents too.

Talking on your cell phone while driving has its own challenges. I find I have to pick and choose the type of conversation to have while in my car -- because I can't take notes while driving. So any conversation that requires absolute concentration and remembering key facts must be delayed until I reach my destination. Or I must be willing to pull over and park while I have my discussion. I must admit that I do this often -- perhaps not often enough -- even though it doesn't completely fulfill my goal of optimizing my time while traveling. It does keep me a bit safer and makes sure that I have the notes from my conversation.

It's also difficult to call somebody who is not in your phone's address book. I keep my contacts in a separate personal digital assistant. So if I want to talk with somebody who has not recently connected with my cell phone and is not in my phone's address book, I have to pull out my PDA and find the contact. My PDA has Microsoft's VoiceCommand, so I can speak into my PDA's microphone to display most contact records, which makes it quick and easy. But it doesn't always find the right record. So I must pull off the road to safely look up the contact.

Not everyone feels as limited while in the car. A couple of days ago, while on my way back to my office from a client visit, I called an associate and left a voice mail message to call me back. Instead of calling me back, he sent me a text message. He expected me to read the text message while driving, and then to use the tiny little keypad buttons on my cell phone to respond. That's not even in the realm of reasoning. I might as well aim at the car in front of me.

Even if I could text-message while driving, I probably wouldn't. As much as I like text-messaging for specific types of communications, I rarely use it -- because it takes me a lot more time to text somebody than it does to call them.

Like any other product, how you use your cell phone depends on your needs and your situation. I'm still waiting for the perfect mobile device -- one that lets me truly optimize my windshield time.