Playing a little with SQL 2008 geometry I thought to post the queries that insert point, lines and polygons for the world to copy and paste if you like
INSERT INTO [Test].[dbo].[GeometryTest]
([Name]
,[Shape])
VALUES
('Test'
,'POLYGON ((5 4, 5.38924515247345 4.0785849690437317, 5.70710676908493 4.29289323091507, 5.9214150309562683 4.61075484752655, 6 5, 5.9214150309562683 5.38924515247345, 5.70710676908493 5.70710676908493, 5.38924515247345 5.9214150309562683, 5 6, 4.61075484752655 5.9214150309562683, 4.29289323091507 5.70710676908493, 4.0785849690437317 5.38924515247345, 4 5, 4.0785849690437317 4.61075484752655, 4.29289323091507 4.29289323091507, 4.61075484752655 4.0785849690437317, 5 4))')
or
Adding a Spatial Reference to the polygon with automatic convertion.
INSERT INTO [Test].[dbo].[GeometryTest] values ('Polygon2', geometry::STGeomFromText(
'POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326));
INSERT INTO [Test].[dbo].[GeometryTest] values ('Line', geometry::STGeomFromText(
'LINESTRING(-122.34799999 47.648999999, -122.34799999999814 47.658000000054017, -122.35 47.65800, -122.35800000000745 47.652999999932945, -123.999 44.999)', 4326));
Create a buffer from a geometry
SELECT TOP (1) Shape.STBuffer(0.001) AS Expr1
FROM dbo.GeometryTest
Get a centroid
SELECT TOP (1) Shape.STCentroid() AS Expr1
FROM dbo.GeometryTest
Get the boundary
SELECT TOP (1) Shape.STBoundary() AS Expr1
FROM dbo.GeometryTest
Resources
http://technet.microsoft.com/en-us/magazine/2008.04.datatypes.aspx?pr=blog
http://technet.microsoft.com/en-us/library/bb933985.aspx
http://sqlspatialtools.codeplex.com/Wiki/View.aspx?title=Current%20Contents