Forum Moderators: phranque
Pros: Live environment with no actual visitors to notice when you screw something up.
Cons: Can't really think of any off hand. Renewal fee every year?
Example, if you have example.com on IP a.b.c.d add the following line to your hosts file:
a.b.c.d example.org
Setup example.org on your server just like you would for a "real" domain.
You should be good to go.
The downside is that you can only do testing from your own computer (unless you make similar changes to the hosts file on other computers). If you're going to have multiple people testing, it probably makes sense to just buy another domain.