"hot standby" system

The documentation [1] says this about On-line backup and point-in- 
time recovery:

> If we continuously feed the series of WAL files to another machine  
> that has been loaded with the same base backup file, we have a "hot  
> standby" system: at any point we can bring up the second machine  
> and it will have a nearly-current copy of the database.

Is this possible today in a stable and robust way? If so, can we  
document the procedure? If not, should we alter the documentation so  
it's not misleading? I've had several people ask me where to enable  
the "hot standby" feature, not realizing that PostgreSQL only has  
some of the raw materials that could be used to architect such a thing.

Thanks!

- Chris

[1] http://www.postgresql.org/docs/8.1/interactive/backup-online.html