SQL Server 2005 actually allows us to parameterize the TOP clause, using a variable, expression or statement. So you can do things like:

select top (@foo) [Column1] from [dbo].[myTable] 
 
select top (SELECT COUNT(*) FROM somewhere else) [Column1] from [dbo].[myTable]
 
select top (@foo + 5 * 4 / 2) [Column1] from [dbo].[myTable]

so we can create parameterized stored procedure with top as input parameter. In Sql 2005 it's simple:

create procedure dbo.getFoo 
    @top INT 
as 
begin 
    select top (@top) percent [column1]
        from [dbo].[myTable]         
end
go