I'm running on 4.1 firmware and I was just wondering if I could jailbreak my phone without having to download any of the greenpois0n, limera1n, etc. to my computer. I would greatly prefer to just do it straight from safari on my phone.
That link is the wikipedia article I googled for you xizif. Looks like 4.0.1 is the latest version it supports. So to answer your question... unfortunately nope... you will need to download an app to JB it for you.