if you go to the user web page you can add up to 100 speed dials. they wont appear on the phone due to physical key limitations, but the "abbreviated dial" feature can be utilized
to abbreviated dial you press the keypad digit(s) associated with the speed dial number while the phone is still on hook. when you press the digit you will get an "Abbrdial" soft key. You press that softkey and it will extend the call. Works well, but users with many speed dials configured will need to print or create a list for themself to reference and keep it nearby or posted near the phone. Kinda hard to remember 100 speed dial references!
also you can setup a personal directory service where users can have a directory of speed dials. Takes a bit more work but is much cleaner and lists all names and numbers.