I'm an input junkie. I type in Dvorak on the desktop. I wrote an app to control the desktop mouse with an XBox 360 gamepad. I wrote all of the input bus drivers for the Sega Dreamcast. I once wrote a driver for a chording data puck because I thought the future of mobile device input was an input system that only someone as crazy as me would adopt....
What follows are a series of tips and tricks for Windows Mobile devices that you don't have to be crazy to appreciate. However, understand that the drivers that control input are written by the OEMs that create these devices. And we don't require that they follow every input quirk to the letter. It's possible that some of these things will work on some devices and not on others.
Smartphone SpecificEasy access to numbers. In both T9 and ABC mode, you can usually get a number by pressing and holding the button. For instance, the 2 button can be a, b, c, or 2. Press it once and you'll get a letter. Press and hold it and you'll get the number. This is a lot faster than switching to 123 mode if you just need to type a few numbers.
Lock the keypad. On smartphones that have a separate power button, pressing and holding the End key (the red button) locks the keypad. Some smartphones don't have a separate power button. On them, the press and hold of the End key is usually power off. In that case, there's often some other key that you can press and hold for lock.
Quicklist. On smartphones that have a separate power button, pressing the power button quickly (not press and hold) brings up the "quicklist." The quicklist lets you do things like toggle flight mode and set profiles. Press and hold the power button shuts the phone off. On devices without a separate power button, one of the other keys will bring up the quicklist (often press and hold Home).
Getting symbols. If you're typing in T9 or ABC mode, there are two ways to type things like period, comma, etc. You can get a table of them by pressing and holding the # key. Or you can get to many of the more common ones with the 1 key.
Speed dial apps. You can assign phone numbers to speed dial keys. Go into the contact, select the phone number you want to put on a speed dial, and then choose Menu->Add To Speed Dial. But you can also assign applications to speed dial keys. From the home screen, hit Start, select the application you want, and then choose Menu->Add To Speed Dial. Once you have a number or application on speed dial, you can go to the home screen and press and hold that number to call or run it. For instance, if you assigned my ToggleBTh button to speed dial slot 2, you can turn Bluetooth on and off by just pressing and holding 2 from the home screen.
Speed dial voicemail. On most phones, speed dial slot 1 is voicemail. So you can dial your voicemail by going to the home screen and pressing and holding 1.
PocketPC SpecificBetter hardware navigation. Some WM5 devices have dedicated "Start" and "Ok" buttons (e.g. the Treo 700w and the Sprint 6700). Some WM5 devices don't have those buttons, but do have two buttons that launch apps (e.g. the T-mobile MDA and the Cingular 8125). Having Start and Ok buttons makes it much easier to control the device without touching the screen. You can change the existing application buttons to do Start and Ok instead. Go to Start->Settings->Buttons. Select the button you want to change and drop down the menu at the bottom. The two you care about are near the top of the list (<Start Menu> and <OK/Close>).
Symbols not on the keyboard. If you have a hardware keyboard that has a "Sym" button (often Fn + Space) you can use it to type symbols that aren't on the keyboard. For instance, say the keyboard has a "/" but no "\". Type "/" then hit Sym. It'll switch. Hit Sym again and it'll switch to "|". This is also a somewhat convenient way to get non-English characters. For instance, if you want an o with an umlaut over it, hit o and then hit the Sym key a few times. It'll cycle through the various accents. Or, if you need the Spanish ñ, hit n then Sym.
What happened to my backlight? On many PocketPCs, if you press and hold the power button it will turn off the backlight and keep it off. This may be what you want, or it may be something you did accidentally and now you're wondering why your backlight never turns on anymore. Press and hold power again to turn the backlight back on. (On at least one PocketPC I've seen recently, press and hold power is a full shut down instead.)
Make the SIP stop coming up. The PocketPC has a "Soft Input Panel" (SIP). This is the little software keyboard that pops up at the bottom of the screen. (It can also be various types of handwriting recognizers, etc.) If the device has no hardware keyboard, the SIP will pop up automatically whenever you get to a place where you can enter text. If there's a hardware keyboard, though, we assume you want to use the keyboard instead of the SIP and don't make it pop up automatically. However, if you tap the little SIP button once, we suddenly decide that you want the SIP to deploy automatically again, even though you've got a hardware keyboard. Maybe you did, or maybe you let a friend look at your PocketPC and he said, "Hey, what's this do?" and tapped it. If you want it to stop coming up automatically, let it pop up once and use the hardware keyboard as though the SIP wasn't there. When you use the hardware keyboard, the SIP will go away and won't come up again until you tap the icon. (The common mistake people make here is to put the SIP away and then start typing on the hardware keyboard. That will put it away, but it'll come back again when you go to a new text field.)
Both PPC and SPPut the call on hold. While in a call, press Send (the green button). That will put the call on hold. Do it again to start the call back up.
Switch to/from speakerphone. While in a call, press and hold Send (the green button) to switch to speakerphone. Press and hold it again to switch back.
I hope you find some of these tips and tricks useful.