Replication questions - read-only and temporary read/write slaves

Hi,
In PostgreSQL, would it be possible to

1. set up a read-only slave database? The closest solution I could find is
Hot Standby but the slave would not be accessible until after a failover.

2. temporary convert a read-only slave in read-write mode for testing
read/write workloads? Currently in Oracle, we can temporary open our
read-only standby database in read-write mode to occasionally test our
read-write workloads. We would stop the log apply on the standby database,
convert the read-only database to read-write,
perform our read/write test, discard all the changes after testing and
reopen and resync the standby database in read-only mode. Is there a
similar feature in PostgreSQL or are there ways to achieve something close
to our needs?

Thanks.

Tiff