I came across this method while working at CSC Volpe. I like it because it does not require detaching the database. Run the following from Query Analyzer while connected to the database you wish to truncate the log for.
sp_dboption ‘<yourDBName>’, ‘trunc. log on chkpt.’, ‘TRUE’
After running these commands run the Shrink Database task from within Enterprise Manager. Your log file should now be about 1 meg.