Hacking is not fully just tools and knowledge.  The valnerability of peoples machines are not their security, but the ability to appeal to the emotions of the user.  You might not believe this works, but recently Microsoft was hacked using social engineering.  A hacker managed to convince a secratary into installing a trojan horse.  Also, the US defense computers are usually hacked using social engineering, but new codes of practice have helped stopped these incidences.  

An example of social engineering is that you go on a chat program and act like you are a female.  You talk to people, talk to a guy, send him a trojan horse but tell him it is a porno game and easily obtain his IP.  It is methods like these that work.

You can chat to someone in the office, pose as a technition, send them a file that you tell them is an antivirus update and has been sent to others in the office.  Before hand, find out the persons name and address the email by appealing to her on first name basis.  Sign the mail by your first name.  Then get her IP... Ahhhh.  Simple isn't it.

Sometimes not much social engineering is required.  You can easily find a html exploit in Internet Explorer, make a rich text email written in HTml using that exploit, change your senders Name to someone who is trusted and senders email address (which is possible in email clients because it isn't needed for server authenication and is needed to just tell the reciever who the sender is) and email it to them using a suitable topic.  This is a very unexpected method and has the added bonus of passing Mcafee virus scan at hotmail because no trojan is attached ;)  

Another impressive technique is actually programming your own trojan/virus (Its actually REALLY easy to do) and using a program to append it to a game or something....  If you write it yourself, it wont get detected.  If you know they have a firewall or antivirus, program something with LOTS of memory leaks.  THe computers ram will get filled up and they will blame the firewall and antivirus.  They will try to free ram and will disable them.... Ahhh... Make them suffer in your Window of opportunity.  A similar method is to ping bomb the target for a while to slow down his downloads. 

As you can see, its easy to be creative and that social engineering is probably the hackers best tool.  Because, little do you realise, but social engineering is used more often then you think !