One poorly-documented feature of the Treo 650 is setting it up to dial extensions after the main number.

I use this to dial into a conference call which requires a 10 digit passcode I never want to have to remember. You can also use it to quickly send a page a to numeric pagers. Trying to dial these long sequences while driving could be fatal.

Strangely you cannot do this in the regular contact list. You have to use a favorites button (that grid that pops up from the main phone screen).

Here’s how to set one up:

1. From the phone, navigate to an empty favorites button using the navigation pad.
2. Hit the menu button then hit the E key to edit the button.
3. Make sure the type is Speed Dial and enter a Label like “Conference Call”
4. Enter the main number
5. Click the “More” button
6. In the Extra Digits box, start by entering a bunch of commas, probably at least 7. Each comma will wait for one second before dialing the digits that follow it. You can also use # and *.
7. Check “Dial Extra Digits Automatically”
8. Click OK and OK again.
9. Try dialing your new Speed Dial button.

It may take a few tries to get the number of commas right. You can listen in as it dials to determine if you’ve got too many or too little.

Anyway, it’s a handy little feature that I use quite a bit.