Here is the script I managed to come up with for the purpose of truncating log files for all databases in SQL Server 2000/2005/2008:
use master
DECLARE @Statement varchar (4000)
SELECT @Statement = ''
SELECT @Statement = @Statement + 'USE [?]; '
SELECT @Statement = @Statement + 'DECLARE @Log_Logical_FileName varchar (100); '
SELECT @Statement = @Statement + 'SELECT @Log_Logical_FileName = rtrim(name) FROM dbo.sysfiles WHERE fileid = 2; '
SELECT @Statement = @Statement + 'BACKUP LOG [?] WITH TRUNCATE_ONLY; '
SELECT @Statement = @Statement + 'DBCC SHRINKFILE(@Log_Logical_FileName,1); '
EXEC sp_MSforeachdb @command1=@Statement
GO