How to jailbreak iPhone 3G iOS 4.2.1?

So I have a iPhone 3G and I want to jailbreak it. I went to a site that said slide to jailbreak. But it doesn't work and I don't wanna plug it up to a computer caus it takes to long. But i will if I have to. So if you know a site that'll let me jailbreak it for free post it.

Jailbreakme.com

Jailbreaking are for people with no iphone skillz

First you go to http://www.jailbreakme.com/ plug in your iphone is will go to the plug into itunes menu take it out and go in the shower with your iphone, next after the shower put the iphone in oven for 350f for about 30-40 min. It will be hot so becareful. Then put it in a bucket of lukewarm water take out and wallllaaaaaaa.jail broken call the cops.

You need a pc and use redsnow.