we are a five-person pediatric practice in north carolina. we would
like to know what our practice is worth? please provide information of
comparable practices in areas with 150,000 population . we have 16000
active patients.

First, after salaries and all other expenses how much is left over
from your income (net income)?  If that figure is just over all your
salaries and expenses all anyone would be buying is a job at the
salary (or close to it) that you are now making.  Your CPA (you have
one right?) should be able to do some preliminary research and give
you a ball park estimate.

Just off the top of my head I'd say 5 - 10 times net income should
give you an amount to consider.

You are a little vague in your question to give even a remote value. 
This is really a $2000 question.

But anyway, first, value the building and equipment seperate from the
practice on a fair market value basis.  what would it cost for someone
to buy those items from stratch.

To do it right, you really have to look at the cash flows the business
is generating.

A good start would be 5 times your average last 3 years of cash flows
mulitple by .75.
In other words.  You do not pay for more than 5 years of cash assuming a discount. 

It depends on so many factors.  Location,competition, you costs
profile to other competitors, etc.etc etc

Another range is to value the practice take your average last 3 years
gross income mulitiply by 30% to 70%.  So if you guys pull down $5 m
in sales.   The practice is worth between $1.5 m to $43.5 m.