I encountered the situation recently where I needed to find the size of the log file. When I tried to find the script by using Search@SQLAuthority.com I was not able to find the script at all. Here is the script, if you remove the WHERE condition you will find the result for all the databases.
SELECT DB_NAME(database_id) AS DatabaseName,
Name AS Logical_Name,
Physical_Name, (size*8)/1024 SizeMB
WHERE DB_NAME(database_id) = 'AdventureWorks'
Reference: Pinal Dave (http://blog.SQLAuthority.com)