What is NEWID() ?
NEWID Creates a unique value of type uniqueidentifier.
Its return type is uniqueidentifier.
[sql]SELECT NEWID() [/sql]
The output of the above query will be a unique identifier, some value like 8845D456-56FF-445Y-DF49-7GGTY54D3E3E
NewID can also be used to sort the rows in randomly as shown below
[sql]CREATE TABLE #TEMPNEWID(COL1 int)
INSERT INTO #TEMPNEWID(COL1)
SELECT 1
UNION
SELECT 2
UNION
SELECT 3
UNION
SELECT 4
UNION
SELECT 5
UNION
SELECT 6
SELECT COL1 FROM #tempnewid ORDER BY NEWID()[/sql]
The above query will give values in table #TEMPNEWID ordered randomly.