Hopefully, you would never find yourself in this position to begin with. But if so, here are the steps to get a working database back with a viable log:
1. Detach database and move your mdf to save location.
2. Create new databse of same name, same files, same file location and same file size.
3. Stop SQL server.
4. Swap mdf file of just created DB to your save one.
5. Start SQL. DB will go suspect.
6. ALTER DATABASE <your db> SET EMERGENCY
ALTER DATABASE <your db> SET SINGLE_USER
7. DBCC CHECKDB (<your db>, REPAIR_ALLOW_DATA_LOSS)
8. ALTER DATABASE <your db> SET MULTI_USER
ALTER DATABASE <your db> SET ONLINE
In SQL 2000, this could be accomplished using the DBCC REBUILD_LOG command, but that is unsupported in SQL 2005.