The following script will show you the number of rows in all the tables in your database.
[sql]

USE DatabaseName
GO
CREATE TABLE #temp (
       table_name sysname ,
       row_count int,
       reserved_size varchar(50),
       data_size varchar(50),
       index_size varchar(50),
       unused_size varchar(50))
SET NOCOUNT ON
INSERT     #temp
EXEC       sp_msforeachtable 'sp_spaceused ''?'''
SELECT     a.table_name,
           a.row_count,
           count(*) as col_count,
           a.data_size
FROM       #temp a
INNER JOIN information_schema.columns b
           ON a.table_name collate database_default
                = b.table_name collate database_default
GROUP BY   a.table_name, a.row_count, a.data_size
ORDER BY   CAST(Replace(a.data_size, ' KB', '') as integer) desc
DROP TABLE #temp

[/sql]