Redsn0w 0.9.6b3

iPhone Dev Team has just released a new version of Redsn0w. The new version comes with OpenSSH that enables you to patch broken Cydia on iOS 4.2 and iOS 4.2.1. Anyway, we'll be back with how to guides after testing it.
 
We’ve made some updates to redsn0w to make it easier for jailbreak developers (and tinkerers) to get their programs ready for 4.2.1. As noted in Update #2 above, the public version of Cydia (and MobileSubstrate too!) is not 4.2.1-compatible. redsn0w will now let you install your own custom bundles independent of Cydia (the bundle can actually be Cydia if you’ve compiled it on your own). These bundles can be up to 15MB in size, and should be in the form of a gzip-compressed tar file.

It’s very important that you get the file permissions and ownerships right in your custom redsn0w bundles. To give you a practical example of such a bundle, here’s one that includes OpenSSH, OpenSSL, and the basic apt installer programs:
Again, don't try to do it yourself, PLEASE CONSIDER THIS AN ADVANCED TOPIC!! It's only meant for professionals out there that can use this feature in the new Redsn0w. Anyway, stay tuned and we'll be back with how to guides.

Download Redsn0w 0.9.6b3 for Windows
Download Redsn0w 0.9.6b3 for Mac OS X
Download SSH Bundle