How do you select all the rows that contain uppercase characters only? There sre three ways to do this
1 Compare with BINARY_CHECKSUM
2 Use COLLATE
3 Cast to varbinary

Let's first create the table and also some test data

CREATE TABLE #tmp ( x VARCHAR(10) NOT NULL )

if we want only the uppercase columns then this is supposed to be our output

WORD
ABC
ZZZ

Let's get started, first up is BINARY_CHECKSUM

Second is COLLATE

Third is Cast to varbinary

Of course if you database is already case sensitive you can just do the following

That will work, how do you find out what collation was used when your database was created? You can use DATABASEPROPERTYEX for that. I use the model DB here because when you create a new DB by default it inherits all the properties from the model DB.
When I run this

I get this as output: SQL_Latin1_General_CP1_CI_AS

What does all that junk mean? Well let's run the following function (yes those are 2 colons :: )

The description column contains this info

Latin1-General, case-insensitive, accent-sensitive,
kanatype-insensitive, width-insensitive for Unicode Data,
SQL Server Sort Order 52 on Code Page 1252 for non-Unicode Data

You can read some more info about Selecting a SQL Collation here: http://msdn2.microsoft.com/en-us/library/aa176552(SQL.80).aspx