Stored Proc to list all object dependencies

EXEC sp_depends 'Object Name'
Go
sp_depends displays information about database object dependencies.
sp_depends displays two result sets. First One shows the objects on which the 'given
object' depends and the second shows the objects that depend on the 'given object'

Query to Check if a table is system table or User table

SELECT OBJECTPROPERTY(OBJECT_ID('TableName'), 'IsMSShipped')
0 --> Indicates User Table
1 --> Indicates System Table

Query to mark a user table as a system table

EXEC sp_ms_marksystemobject 'TableName' Go

dtproperties Table in SQL Server 2000

dtproperties is a system table that stores the information about the Database Diagrams created in a particular database. Whenever a Database diagram is created or modified this table
gets updated automatically.

Basically this is a system table but when we run the below query we will get the name of
dtproperties table in the result set, indicating that this is user table.Microsoft has
confirmed that this is a bug in the Microsoft SQL Server.

Select * from sysobjects where xtype='u'

Finding Difference between Tables in SQL 2005

In SQL 2005 the difference between tables can be easily found by using the tool
TableDiff.exe.
TableDiff.exe is a comparison tool that is provided with the sql server.
It will be found in the following location:
"C:\Program Files\Microsoft SQL Server\90\COM\TableDiff.exe"
The Drive name depends on where the SQL is Installed.
This tool compares 2 tables of the same database on the same server and creates a new
table called new Table that holds the differences.

"C:\Program Files\Microsoft SQL Server\90\COM\tablediff.exe"
-sourceserver ServerName
-sourcedatabase DatabaseName
-sourcetable TableName
-destinationserver ServerName
-destinationdatabase DatabaseName
-destinationtable TableName
-et NewTableName

For more information on this utility check out the microsoft website:
http://msdn2.microsoft.com/en-us/library/ms162843.aspx