I found these tricks on the android community forum and thought they were useful enough to publish.
Holding the home button brings up your 6 most recent apps.
To activate the magnify glass on the browser click the trackball twice.
To make ringtones, alerts, and notifications make a folder inside your memory card each one containing there own name such as “ringtones” “alarms” “notifications”
Turning off the GPS saves battery life to do so go to Menu, Settings, Security and Location.
To rename a folder on the homescreen click and hold the dock at the top of the folders name.
When you want to change a setting just about anywhere on the phone hit menu, it’ll give you options.
Long press the phone key for voice dial.
In browser, and also in pic gallery-
when the zoom + - shows up- you can hold the + down and it will smoothly keep panning in.
To Cut, press Menu and x.
To Copy, press Menu and c
To Paste, press Menu andv
Switch phone orientation to landscape:
In web browser, go to menu>more>flip orientation. This will change the phone orientation to landscape so that you don’t have to open the screen to get it to flip.
Clear your Cache!
If you’ve been using streetview or the browser alot, the cache can quickly get big. I’ve only had the phone for two days and got 20MB back by clearing the cache on these two.
Settings > Applications > Manage Applications > Browser > Clear Data
Settings > Applications > Manage Applications > Streetview > Clear Data
Saving pictures from the web:
Press and hold the image for 3 seconds, a selection will pop-up either to save image or view image. It may contain more selections if the image contains a link.
In the browser, hold down ALT key and roll trakball for fast scrolling.( Or press space bar for a fast scroll down)
To forward picture and text messages: Press and hold the message.
Use AnyCut (Application in Android Market) to put important contacts on your desktop, I usually use the text one because it’s also useful if you want to call them, just pull up the text screen then hold your finger on their phone number and you can view contact and call them from there, of course you can use AnyCut to make it go straight to their contact info, but I usually am texting people so that’s why I used text.
-in browser, long press trackball/pearl on image to bring up “save image/view image”
-in browser, long press trackball/pearl over url to bring up “open/open in new window/bookmark link/save link/share link/copy link url”
-in browser, press menu to bring up browser menu (go to url/search/bookmarks/…etc); long-press menu to temporarily flash the shortcuts