Identify NON-ANSI joins in SQL Server 2008 R2 on a Database that's in 2000 (80) compatibility mode
This may produce some false positives (e.g. you may have *= in a comment), but should be a good start:

SELECT 
  obj = QUOTENAME(SCHEMA_NAME(o.[object_id]))
      + '.' + QUOTENAME(o.name),
  o.type_desc
FROM sys.sql_modules AS m
INNER JOIN sys.objects AS o
ON m.[object_id] = o.[object_id]
WHERE m.definition LIKE '%=*%'
OR m.definition LIKE '%*=%';