I find the keyboard on the T-Mobile G1 "smart phone" a tad awkward to use. After all, I am a 110+ wpm touch typist when I can use all 10 of my fingers. Typing with my thumbs is frustratingly slow. But I am getting a little more comfortable with the keyboard every day and already I am able to type faster than I expected to be able to, and I make fewer mistakes than I thought I would.
I think it's better to have a full QWERTY keyboard than to have to type with just the normal dialing pad pad of a phone, where, to type the letter "c" you must hit the "2" key three times! And although I have never typed more than a few words on an iPhone, I think I prefer to have a "real" keyboard rather than a virtual one. I read a statistic a month or two ago that noted that iPhone users account for a disproportionately high percentage of mobile access to the Web - and for a disproportionately low percentage of text messages; the explanation offered was that the iPhone is great for browsing and reading but not so great for typing. I suspect I would feel the same way. On the other hand, there are types when it would be nice to have a virtual keyboard on screen as an option. I have occasionally wished that I could type something simple like a phone number without having to open up the phone to get to the keyboard.
I really wish Android had a utility to auto-expand typed shortcuts, like As-U-Type on the PC or TypeIt4Me on the Mac. It would be a huge help on the small keyboard. The underlying technology seems to be there, because Android already can turn a lone "i" into a capital "I" and can turn two spaces in a row into a period and a space. So the OS is already monitoring keystrokes and can be asked to back up and make quick corrections. Now somebody just needs to figure out how to extend that capability to the "correction" of a user-configurable list of shortcuts, so I could type "tm" and have the phone auto-correct that to "T-Mobile" and so on.
One thing that I love about the way Android handles text entry is the ease with which you can enter accented characters. To type the accented é in "idée" or the enya in "piñon", you simply type the letter and hold it down for half a sec, then select the option you want: è or é or ê or ë. An excellent typist using a Mac can probably enter accented characters even more quickly. But the Mac OS method involves modifier keys and would be hard to implement on the G1. Android's method is certainly a spectacular improvement over what you must do on a PC! I gather that the Apple iPhone uses the same UI trick to enter accents. If Google swiped the idea from Apple, then I have to give Google credit for recognizing a good thing.
Another nice thing about Android's text handling is that you can cut, copy and paste text.
Don't think I'm going to be typing any lengthy epistles on the G1. But for short messages, it's surprisingly satisfactory.