Another way, no cursor but still not amazing.

declare @sql varchar(MAX)

set @sql = ''

create TABLE #temp (ID INT IDENTITY (1,1) PRIMARY KEY CLUSTERED, ServerName sysname, DBName sysname, Size int, ReadingDate datetime)

select @sql = @sql + 'INSERT INTO #temp (ServerName, DBName, Size, ReadingDate) select @@ServerName, ''' + name + ''', Size, GETDATE() from [' + name + '].[dbo].[sysfiles];'

from master.sys.databases

EXEC (@sql)

SELECT * FROM #temp