This one seems better:

create table #dbusedsize ( name nvarchar(50), used_mb int)

DECLARE @SQL VARCHAR(1000)

DECLARE @DB sysname

DECLARE curDB CURSOR FORWARD_ONLY STATIC FOR

SELECT [name]

FROM master..sysdatabases

WHERE DATABASEPROPERTYEX(name, 'Status') = 'ONLINE'

OPEN curDB

FETCH NEXT FROM curDB INTO @DB

WHILE @@FETCH_STATUS = 0

BEGIN

SELECT @SQL = 'USE [' + @DB +']' + CHAR(13) + 'INSERT INTO #dbusedsize( name, used_mb )

select name, FILEPROPERTY([name], ''SpaceUsed'')/128

from sysfiles sf left outer join sysfilegroups sfg on sf.groupid=sfg.groupid

order by 1' + CHAR(13)

--Print(@SQL)

Exec (@SQL)

FETCH NEXT FROM curDB INTO @DB

END

CLOSE curDB

DEALLOCATE curDB

select name, SUM(used_mb) from #dbusedsize

group by name

drop table #dbusedsize