http://chronic-dev.org/blog/2010/10/greenpois0n-initial-release/

greenpois0n only works on firmware 4.1, so (only if you have an iPhone 4!) if you are on a lower firmware make sure you use TinyUmbrella to preserve your baseband.

Download: http://www.greenpois0n.com/

Initially, this will be a Windows-only release. This is due to some technical complications that we soon hope to correct. We apologize for any inconvenience.

Thanks to geohot for the bootrom USB exploit. We have opted to use that instead of SHAtter for the sake of exploit presevation.

This release of greenpois0n supports:
- iPhone 4
- iPhone 3G S
- iPod touch (4th Generation)
- iPod touch (3rd Generation)
- iPad

Soon there will be another release, adding things like support for:
- Apple TV (2nd Generation)
- iPod touch (2nd Generation)

http://bbs.weiphone.com/read-htm-tid-1207066.html