Although it's a general recommendation to have a clustered index on a table, not every application is following this guidance. Since heap tables can't be defragged or can't get rid of forwarded records, use this script to determine potential problems. I developed this script after we had some serious problems with a heap table.
Tables with a high fragmentation/ forwarded record count or ghost record count can be fixed by either creating a clustered index or do the traditional export-truncate-import (make sure you're aware of the consequences of these actions!)
Note: By running this script your "page life expectancy" will drop significantly (due to the dm_db_index_physical_stats usage)
New version: added parameter for tablename criteria. Output by RAISERROR instead of PRINT
NOTE: if this script is not working, copy/past it into an editor and remove goofy characters