View blocking, SQL Server 2005 and above

with blocked
as
(
--first, the processes being blocked
select * from sys.sysprocesses where blocked>0
--second, blocked processes being blocked further
union all
select p.* from sys.sysprocesses p
inner join blocked b
on p.spid=b.blocked
)
select getdate() checkTime,b.*,t.text into #blockChain from blocked b cross apply sys.dm_exec_sql_text (b.sql_handle) t;

select getdate() checkTime,l.* from sys.dm_tran_locks l join #blockChain b on l.request_session_id=b.spid
where blocked=0

drop table  #blockChain

--use dbcc inputbuffer (spid) to check individual spid's last execution.
--sp_lock spid

Another query copied from the Net:

SELECT  L.request_session_id AS SPID,
        DB_NAME(L.resource_database_id) AS DatabaseName,
        O.Name AS LockedObjectName,
        P.object_id AS LockedObjectId,
        L.resource_type AS LockedResource,
        L.request_mode AS LockType,
        ST.text AS SqlStatementText,       
        ES.login_name AS LoginName,
        ES.host_name AS HostName,
        TST.is_user_transaction as IsUserTransaction,
        AT.name as TransactionName,
        CN.auth_scheme as AuthenticationMethod
FROM    sys.dm_tran_locks L
        JOIN sys.partitions P ON P.hobt_id = L.resource_associated_entity_id
        JOIN sys.objects O ON O.object_id = P.object_id
        JOIN sys.dm_exec_sessions ES ON ES.session_id = L.request_session_id
        JOIN sys.dm_tran_session_transactions TST ON ES.session_id = TST.session_id
        JOIN sys.dm_tran_active_transactions AT ON TST.transaction_id = AT.transaction_id
        JOIN sys.dm_exec_connections CN ON CN.session_id = ES.session_id
        CROSS APPLY sys.dm_exec_sql_text(CN.most_recent_sql_handle) AS ST
WHERE   resource_database_id = db_id()
and L.request_session_id in ()
ORDER BY L.request_session_id