Passing a dynamic table name to a stored procedure

Is this possible?

I know this doesn't work but I'll post it anyways so you can see what I'm trying to accomplish.

CREATE PROCEDURE GetStuff
 @.something int,
 @.tablename varchar(50)
AS
 SELECT * FROM @.tablename WHERE something = @.something

Like I say, I know it doesn't work...but does anyone know how to accomplish something like this?there are some limitations to this code but it works for most parts :
using NOrthwind database :

CREATE PROC sp_distinctcount
 @.table_name AS SYSNAME,
 @.cat AS int
AS
DECLARE @.sql AS nvarchar(1000)
SET @.sql = N'SELECT *'+ N' FROM ['
 + @.table_name + N'] where categoryid=' + convert(varchar(10),@.cat)
EXEC sp_executesql @.stmt = @.sql
GO

from QA :

EXEC northwind..sp_distinctcount
 @.table_name='categories',@.cat=1

hth