I've got a few more:

• To turn NUM lock on (to type only in numbers and symbols) Press the Alt key and the Shift key.
• To turn NUM lock off, Press the Alt key.
• To highlight text, Press Shift and roll trackball over text.

When viewing the Calendar:

• To change to Agenda view, press A.
• To change to Day view, press D.
• To change to Week view, press W.
• To change to Month view, press M.

When Messaging:

Within a message:

• To reply to a message, press R.
• To reply to all, press L.
• To forward a message, press F.

In Message List:

• To compose a message, press C.
• To view received messages, press the Alt and I keys.
• To view SMS text messages, press the Alt and S keys.
• To view call logs, press the Alt and P keys.
• Press escape at anytime to go back to message list.

While Internet Browsing:

• Press escape to stop loading a page.
• Press and hold the escape button to exit the browser.
• Press K to open bookmark list.
• Press A to add a bookmark.
• Press Z to switch between column view and page view.
• Press I to zoom in.
• Press O to zoom out.
• Press H to return to home page.
• Press R to refresh a page.

For Blackberry Maps:

• Press I to zoom in on a map.
• Press O to zoom out on a map.
• Press U to hide status information at the top of a map.
• Press N to move in next direction on a route.
• Press P to move in previous direction on a route.

Media Player:

• Press the mute key to pause or resume playing a video or song.
• Press N or Volume Down keys to play the next song.
• Press P or Volume Up keys to play the previous song.
• Press L to rotate a picture.
• Press R to zoom in to a picture.
• Press C to zoom out from a picture.
• Press Alt and 7 keys to return to picture's original size.
• Press W to fit picture to screen.
• Press Space to pause or resume a slide show.