I've been using iDialer and iContacts. Think I saw a companion for them, iAvatar if I recall correctly; basically just the contacts app with thumbnails.
In a nutshell, these lightweight apps dial your GV# and handle all the login & dialing, making it 1-touch for contacts, and straight dialing for other numbers.
You do need to go to their website for a custom cab; they add in your pin & GV# to the install. I haven't tried the Avatar companion yet, but the other two work well. Enjoy.
iDialer
iContact
iAvatar