still much better then a 20 to sub 20 mpg suv..
I replaced a Chevy Blazer with a 2005 Toyota Prius.  This change is typical of the many Prius owners here in Austin.  After the break-in period and with some driver training, 52 miles per gallon is what I get on a daily 23 mile round-trip commute on the highway.  But for fun I sometimes make the same commute on slower city streets and use the "Pulse and Glide" technique which is mostly coasting under 40 MPH with neither gasoline nor electric engine engaged - I get 65-70 MPG.

Most people don't know that the Prius is also a PZEV (Partially Zero Emissions Vehicle) in which the first few minutes of driving have quite low MPG in order to minimize polutants.  The on-board real-time MPG display usually shows less than 30 MPG average for the first five minutes.

I recommend the car for those who can afford one and in particular for those who do mostly stop and go driving.  

in which the first few minutes of driving have quite low MPG in order to minimize polutants.

How does getting worse MPG lead to less polution?  There must be something I'm missing here.

the car's warm-up cycle burns extra gas to get the catalytic converter hot as quickly as possible to reduce emissions

http://priuschat.com/forums/kb.php?mode=article&k=14

I recommend the car for those who can afford one and in particular for those who do mostly stop and go driving.
The entire New York City yellow taxi fleet should be converted to Priuses as the existing cars age out. That's 12,778 cars, each of which does nearly nothing but stop and go traffic for 24 hours a day (two shifts per car). It looks like the city's taxi regulatory agency has authorized the following models:
2006 Ford Escape Hybrid, 2006 Mercury Mariner Hybrid, 2006 Toyota Highlander Hybrid, 2006 Toyota Prius, 2006 Honda Civic hybrid, 2006 Honda Accord hybrid, and the 2006 Lexus RX 400H.
That's interesting: there's no GM product on your list.  I seem to recall that after the demise of the traiditonal NYC Checker cab in the 1970's, the fleet was largely Chrevrolet Caprices or Ford.Mecury Town Car of similar bulk.  Size is a definite factor for the taxi fleet,and it's hard to imagine the prius being large enough to pack people in.
Victoria, BC taxi company is into the Prius in a big way (relative to size of fleet):

http://www.empresstaxi.com/

<snip>...90 passenger vehicles in total, that include over 33 Toyota Prius (Hybrid) vehicles...</snip>

Two years ago I looked at the Prius & Insight and went anotehr direction, a low mileage (73,800) 1982 Mercedes Benz 240D (manual transmission).  My experience (synthetic lube everywhere) is 31 mpg city and 35 to 42 mpg highway (depending upon speed).

Not as good, but good enough for my low annual mileage.

Greater durability, higher quality construction, biofuel option (the older M-B diesel fuel pump is uniquely suited to a variety of fuels), probably greater safety and lower cost (I won eBay bid at $10,500) than anew car.  And I have confidence that, absent an accident, it will be my last car (I am 52 and this should last me into by 80s, if I live/drive that long).