You can use voice dial by number now.

That's a phone issue. The Cingular Blackberry Pearl will send all
contacts at once. Although it's got to be impossible to keep up with
all the phones as quickly as they are released, lexus.com has a chart
that outlines what features work on each phone they've had a chance to
test.

That's still the same on the latest gen nav, unfortunately. "John
home, John work, John Cel" all need their own entries (as you've
discovered).

You can enter name/phone #s directly into the phone database on the
latest gen nav, but then you'd also have to enter it into your phone,
so you're entering it twice?

To clarify, the one-at-a-time is a phone software issue. lexus.com
lists all the phones they've been able to test along with the features
that work. For example, the Cingular Blackberry Pearl allows entire
phonebook transfer instead of one at a time.

That hasn't changed with the latest gen nav... :(

You can enter a name/number directly with the latest nav, but why
enter it into both your phone and the nav when you only need to enter
it once into your phone and then transfer to the nav?

If you don't have a stored entry, voice activated dialing by stating
the numbers wouldn't be bad? What's not to like? That being said,
you'd still have to read off the numbers from a scrap of paper while
simultaneously driving. Any type of dialing, by hand into a keypad or
even by voice, diminishes your concentration while driving.

Well, the transfer one number at a time thing is actually phone-
dependent, and not a fault of the car.  Some phones can do the entire
phonebook at once (my husband's old Sony Ericsson T68i for example),
while others can only do one contact at a time (his current Motorola
RAZR for example), while some cannot transfer at all (like the
notorious Verizon V710).

Yes, there is the issue that the first number attached to a name is
the one that is transferred.  The only real way around that is to only
have one number attached to a name in your phone book, something like
John Smith H, John Smith W, John Smith C (one entry each for John
Smith at his home, work, cell numbers).  Hopefully the first number
you entered isn't a fax machine! ;-)

On the Prius and several other Toyotas (Camry, Sienna, Highlander HV,
and Lexus RX400h that I've heard of), depending on the implementation
there may be a screen hack that'll disable the navigation/bluetooth
speed lockouts.  (The display used on the 2004-2005 Prius uses this,
but it is not available on the 2006-current Prius...)
Give
http://hybridcars.about.com/od/ownership/ss/navigation.htm
or
http://www.wikihow.com/Override-Toyota-Prius-Navigation-Gray-out
a try...

Is there any chance that you can program your customers as a POI if
you have a navigation package?  I think that you can dial a POI while
moving, if you can still access the POI.

You can enter a phone number into the phone book of the car without
the use of downloading from your phone, but it is kinda tricky.  On
the newer display I mentioned (for a Prius it's on the 2006 and newer
models, I don't know when the crossover is/was on other Toyota/Lexus
models), you can directly add in a number to the phonebook (while car
is stopped).  Otherwise (either display version), you can transfer a
number from the quick-dial location that stores the previous outgoing
or incoming calls and place that stored number into the phonebook
(although without a description).  Alternately, you can add a phone
number to a POI in the navigation system and dial it from there.