i use an app called speed dialer. it has a widget that shows 4 contacts and u just tap the picture to call them. additionally, u can scroll the widget left and right to display more quick dial contacts.
Put about 8 of my favorite contacts on my home screen with one touch press to dial. When you open Bettercut you get the direct dial option. I believe it defaults to Google contacts if they are on your phone.
"Quick contacts widget" built into the phone (under motorolla widgets) works fine for this. If you have more than one action set for a contact (mobile phone, home, texting) then it will bring up a window to ask which one you want to use, but if you only have one option set up on a contact the window will come up the first time, and you can check a box that says "enable one touch dialing for this contact" which does exactly what you want. I decided two-touch dialing was good enough to avoid accidental calls, but if you like it it is available for you.
long press on blank space.
------>Contact Quick Tasks
(Only choose 1 number for the contact)
--->Resize the block to only 1 X 1
------>First time you try to use it you will be asked.
"Enable One-touch calling for this widget"
If you do this you will end up with a 1x1 icon that if you press it will direct dial in 1 press... I really had to dig to find this. It was right on the Moto Droid 1. I now have the moto droid 2. Why would they burry this?
+1 on what edgeman4 and jns.das said. I also like that you can configure it to bring up work, cell and home numbers on the first press and then you get to choose which one to call with your second press.