Clearly, the Multitouch capable touch screen is one of the better features of the G1 phone. Although I’ve found it to be somewhat less refined than the iPhone’s touchscreen (for example, the inability to zoom in and out by “pulling” and “pushing” with two fingers is consistently maddening), it’s effective.
Since, as a rule, I don’t read product manuals, I discovered most of the extended features of the touch screen by accident:
Moving An Icon and Killing the Analog Clock: Go to the Home screen. Touch and hold the icon or offending widget for about 2 seconds. The phone makes a reassuring “buzz” to let you know you’re moving something, and the application slider becomes a trash can. Drag the icon/widget there and let go to kill it. Drag to a different part of the screen to reposition.
The Lauded Copy/Paste: A true iPhone killer. If the text is in a text box (as with an online form), touch and hold for 2 seconds. Choose “Copy” in the resulting menu. Repeat elsewhere to paste.
Double Click: I find that, when the screen is being difficult, it helps to do a fast double-tap. This seems to work especially well for opening apps.
Selecting Text: Android seems to pull the following bits of information out of emails, websites, etc: street addresses, URLs, and phone numbers. Touch these and hold to add to contacts and whatnot.
Moving Around Within Text You’ve Written: Say you’ve written something, like an email, and you want to make changes. Ideally, you’d want to be able to click somewhere earlier in the email and use the delete key, like with a word processor. I’ve found that the touchscreen is consistently bad for this–it’s hard to get to the right point in the text. Instead, I’ve taken to using the little scroll ball–you can move around much more accurately and kill offending typos far faster.