Another lovely feature of XP: It used to be that l33t haxx0rs had to fool you into installing Sub7 or Back Orifice before they could 0wn j00. But now, with "Remote Assistance", being 0wned is now much, much easier!

From Microsoft.com:
The Remote Assistance tool in Windows XP lets you get hands-on help from a tech-savvy friend, family member, or support professional who also runs Windows XP. The expert can be in the next room, or the next time zone. As long as you have an online connection, your helper can remotely take control of your computer. You can watch and chat in real time as he or she fixes your problem. Remote Assistance is secure because you give control only to a trusted individual, and you can take back control anytime.

Translation:
AOL Chat Room: Windows XP Help

***CluelessUser69 has entered the room.

CluelessUser69: My cupholder is broken can ne1 pls help me?

H@xx0r666: d00d i can help you IM me u password i will use remote assistance!

CluelessUser69: OK here it is thx!
H@xx0r666 uploads a small .exe that disables the function where you can "take back control anytime" and possibly even the power button (I also saw on tomshardware.com that you could select what you want to do when the power button is depressed...), and proceeds to delete all of CluelessUser69's files.

And that's if the passwords are reasonably secure....