Locking SharePoint Site for Read/Edit

We can use a stsadm command to lock a Sharepoint site for further read or write when we are doing the maintenance on the site. This feature comes really handy.
The command to use for this purpose is:
stsadm -o setsitelock -url http://localhost -lock {none noadditions readonly noaccess}
Here we have 4 kind of locks available:
None: This option sets the site collection to unlock. With this site will be open to read and write.
Noadditions: This option stops any new addition to the data. Suppose we have 1000 character in a list. With this option user can reduce this 1000 char but can not further add any character.
Readonly: With this no write operation will be allowed. Site will become read only.
Noaccess: This value sets the site collection unavailable to all users. User can not access the SharePoint Site.
Also we can use the following STSADM command to get the lock status for the site:
stsadm -o getsitelock -url http://localhost