Is your phone jailbroken? I'm using an app called SpringDial which allows me to add contacts (with Address Book images as their icons) to the Springboard. I have a page just for "speed dials."
(I did notice, however, that it didn't work right the first time I downloaded it. It would hang just after clicking an icon. This has something to do with a conflict with Summerboard. Somehow, though, I got it to work on my second install. I love it.)
I found it easier to assign the HOME button to the Phone favorites. Then I just double click and I'm at my favs screen which allows me to speed dial sort off.
I suppose putting a "webclip" (per 2nd poster??), or using a 3rd party apps saves me from pressing the HOME button twice.
Hey Guys! Release from JustLikeEd hosted by Spike_132000!
Put Contacts on your springboard!!!
All you have to do is:
1) goto Click Here - http://dial.foa.me/ - No information is stored on any servers, just so you know!
2) enter a name and phone number
3) press Create Contact Page
4) Click '+' and click Add to Home Screen
5) Click Add
6) then just press the new shortcut on your homescreen!
7) when prompted press Call