This site will let you practice your l33t skills at haxoring.
The site is pretty self explanatory.
From the about page:
OverTheWire.org / PullThePlug.org is a non-profit organization aimed at nurturing the growth and development of the information security field through community-wide research and development projects, lectures and wargame servers. Rather than taking the usual approach of hands-off documentation, we emphasizes education and development as a community effort.
There are also some guides and videos to help you along the way. There is plenty to do so have a look around.
Is there any catch to doing something like this?
A third party security audit is the IT equivalent of a colonoscopy. It's long, intrusive, very uncomfortable, and when it's done, you'll have seen things you really didn't want to see, and you'll never forget that you've had one.
I'm a compulsive post editor, you might wanna wait until my post has been online for 5-10 mins before quoting it as it will likely change.
I know I seem harsh in some of my replies. SORRY! But if you're doing something illegal or posting something that seems to be obvious BS I'm going to call you on it.
There are lot's of sites like this, you won't get any visits from people in black suits, since it is not illegal they can't do anything, it is all for fun. I use to do stuff like that years ago, but got bored of it. They say I don't have ADD I think I do.