If you're tech savvy enough, you might be able to pull this off. The following videos will show you how to use PSFreedom to jailbreak (softmod) your Sony Playstation 3 using a jailbroken iPhone 3G or iPod Touch.
If you own a Palm, you could also download the PS3 Jailbreak software and run it on there while it's connected via USB to your PS3. Video of how to do that below: