Return Only The Most Recent Record/row In A Table

Given the Patients and PatientVisits tables as per below, how do I obtain the most recent (latest) Weight and Height for each patient as per http://www.hazzsoftwaresolutions.net/selectStatement.htm
The result of the query should only return 3 rows/records,not 5. Thank you. Greg


Code Snippet
select p.ID, p.FirstName,p.LastName,DATEDIFF(year, p.DOB, getdate()) AS age
,pv.WeightPounds, pv.HeightInches
from Patients as p
inner join PatientVisits as pv
ON p.ID = PV.PatientID
order by pv.VisitDate desc

INSERT INTO Patients (ID, FirstName,LastName,DOB)
select '1234-12', 'Joe','Smith','3/1/1960'
union
select '5432-30','Bob','Jones','3/1/1960'
union
select '3232-22','Paul','White','5/12/1982'
INSERT INTO PatientVisits (PatientID, VisitDate,WeightPounds,HeightInches)
select '1234-12', '10/11/2001','180','68.5'
union
select '1234-12', '2/1/2003','185','68.7'
union
select '5432-30','11/6/2000','155','63.0'
union
select '5432-30','5/12/2001','165','63.0'
union
select '5432-30','4/5/2000','164','63.5'
union
select '3232-22','1/17/2002','220','75.0'

CREATE TABLE [dbo].[Patients](
[PID] [int] IDENTITY(1,1) NOT NULL,
[ID] [varchar](50) NULL,
[FirstName] [nvarchar](50) NULL,
[LastName] [nvarchar](50) NULL,
[DOB] [datetime] NULL,
CONSTRAINT [PK_Patients] PRIMARY KEY CLUSTERED

CREATE TABLE [dbo].[PatientVisits](
[ID] [int] IDENTITY(1,1) NOT NULL,
[PatientID] [nvarchar](50) NULL,
[VisitDate] [datetime] NULL,
[WeightPounds] [numeric](18, 0) NULL,
[HeightInches] [decimal](18, 0) NULL
) ON [PRIMARY]