So, what I tried was setting my top 5 or so numbers in the iPhone as:
01 Wife
02 son
03 daughter
04 Home
05 Office
Etc etc (using whatever names I wanted, such as real first name etc etc)
I set these numbers in front of the first name as I have the sort by first names, so if you sort by surname then put the numbers on the surname.
Then when selecting "directory" the first lot of names that come up from the top down are the ones you want as speed dials. Sure it's still not a single step process but it is really easy and liveable. I can bare it with this setup and the missus reckons I'm "fairly anal". I think she's too polite to call me OCD!
Good luck
