Type this query to find them:
 
SELECT
T1.Name as DatabaseName,
COALESCE(Convert(varchar(12), MAX(T2.backup_finish_date), 101),’Not Yet Taken’) as LastBackUpTaken,
COALESCE(Convert(varchar(12), MAX(T2.user_name), 101),’NA’) as UserName
FROM sys.sysdatabases T1 LEFT
OUTER JOIN msdb.dbo.backupset T2
ON T2.database_name = T1.name
GROUP BY T1.Name

ORDER BY T1.Name