What can I do if the domain I want is already taken?

Unless you have a super unique name, chances are pretty good that someone already had the same idea in the past 25+ years of open DNS registrations. This is an area where you need to tread lightly. If someone already has domain.com, but domain.net is free, don't just jump on that. Do some research and make sure that the owner doesn't have a trademark, or can make a claim of such. It is very difficult to win this battle if you weren't first. Instead, you should try and think of alternate words or combinations that evoke the same idea. With all the new TLD's out there now, you can make some pretty unique combinations that surely aren't taken yet!