Hi Naomi,
>Do you know if this is available in SSMS in SQL Server 2008 Express?
I don't know if it's in 2008. It is in the Express edition for SQL 2005, though. There you need to double click Management > Activity Monitor to get the Process view. Right click on Activity Monitor to view locks by object or process. I guess that it's the same in 2008, but I don't know for sure.
--
Christof