A handle: The username and password used to connect to Sony based servers.
------ basically, when you got your PSP, it should have came with a red piece of paper with a series of numbers and letters on it. - that is your access code.
Enter that onto: http://www.yourgamingname.com - then you can start playing online on Killzone Liberation. The handle is the username basically, you choose that when you enter your network access code on yourgamingname.com, mine is: KCOVINGTON -and then you choose a password with it and you should be online with killzone, and trust me, that is a good, good, great, fantastic thing... because killzone liberation online rocks the house!! - if you need help with next steps, just respond to the forum buddy!! :-)
Hope this helps.
Wait a sec. I don't think I ever got a red piece of paper when I got my PSP SLIM. I got the bundle pack. Sliver version and there wasn't any Red Paper in there. They didn't even give me my receipt, I payed by credit card too. WTF? Where's the handle??? I haven't signed up at that yourgamingname thing yet.
I created a thread about this stuff, it has some very useful information on it, including a number to call up!