2. Click View, Toolbars, Quick Filter Bar. (If there's already a checkmark next to Quick Filter Bar, you don't need to click it.) The Quick Filter Bar resides just above your inbox. Even if it was already there, you might never have noticed it or bothered to fiddle with it.

3. Just to the right of where it says "Quick Filter," there's an icon that looks like a tiny pair of sunglasses. Click it.

Presto! Now your inbox shows only unread messages -- and fits a lot more of them into view. I find this insanely handy. And the icon is a toggle switch, so you can just click it again to restore the usual all-messages view.

Neat, huh? While you're at it, check out my Thunderbird tips on and .

Contributing Editor writes about business and consumer technology. Ask for help with your PC hassles at hasslefree@pcworld.com, or try the treasure trove of helpful folks in the . Sign up to have the e-mailed to you each week.