Mentioned this site on IRC, and there was interest from a couple people on there so I thought it would be beneficial for me to post it here as it seems not everyone knows about it.
Link:
OverTheWire (
http://www.overthewire.org/wargames/)
This site has practice for essentially every kind of hacking and pentest you could think of. A team I'm on at my University used this site as the main practice tool, and we placed incredibly well in an international CTF competition.
The site also updates regularly, and continues to add more challenges and expand on their current ones. There's many different categories, and I don't know anyone who has finished them all yet. So even you experts out there should be kept pretty busy with this site.
Hope you all enjoy.
Lupus
