Redsn0w, the prominent jailbreaking tool developed by veteran of the scene MuscleNerd, has today been updated to version 0.9.9b1 and brings with it some key improvements, rendering it one of the most significant updates to date.

Whilst Redsn0w has done a terrific job of enabling the jailbreak of any iOS device bar the iPad 2, the process is somewhat elongated by the necessity of downloading the entire .iPSW file specific to the device in order to carry it out. The joy of using the likes of Comex’s JailbreakMe or the Chronic Dev Team’s Greenpois0n tool is that one doesn’t have to download those bulky (600mb+) files in order to quickly free the iPhone, iPad or iPod touch of that metaphorical ball and chain.

MuscleNerd has addressed this issue with the very latest update, released just minutes ago. Redsn0w detects and automatically downloads the essential files from Apple’s servers required to perform the jailbreak. Additionally, it stores those files in its cache, preventing the need to re-download for the purpose of carrying out the jailbreak again in the future. The system works for both tethered and untethered jailbreaks depending on the progress that has been made with said version of iOS.

Please note that the ‘scan and store’ of the essential files does NOT apply to the iOS 5 Beta releases. Those wishing to jailbreak one of the several incarnations of iOS 5 Beta will need to go about it the old school way and provide the full .iPSW in order for it to work. This limitation is placed because iOS 5 Betas are not available to public.

Changelog

uses DFU mode to try to automatically determine which device and FW you have
fetches pieces of public IPSWs from Apple (once). Non-public IPSWs must be provided manually (once). It then caches those pieces for future use.
“Just boot” is a tethered boot. Uses whatever “Preferences” you’ve set for boot logo and kernel boot-args
“Pwned DFU” puts your device in a pwned DFU state for some of the iTunes stuff detailed below
“Recovery fix” gets past 1015 types of errors (when baseband portion of restore fails). Should work on iOS5 beta too
“Select IPSW” is for picking non-public IPSWs, or overriding auto-detection
“SHSH blobs” has a bunch of options…
“Fetch” – fetch current PARTIAL blobs on device. Should complete in under 10 or 15 seconds. Puts the set of PARTIAL of blobs on your computer as a plist. Checks if Cydia already has a full set for this device and build. If not, it submits this PARTIAL set and returns Cydia’s acknowledgement or rejection
“Verify” – cryptographically verifies existing blob files from either redsn0w, TinyUmbrella, or Cydia server. You can select a whole bunch of blobs to verify at once if you want (like the TinyUmbrella directory)
“Submit” – both verifies and submits one or more blob files to Cydia. This lets you copy your entire TinyUmbrella cache of blobs up to the Cydia server
“Query” – queries the Cydia server for all available FULL or PARTIAL blobs for a given set of ECIDs
“Stitch” – stitches either FULL or PARTIAL blobs to a STOCK or CUSTOM IPSW
FULL blobs stitched to a STOCK IPSW gives you a completely self-contained signed IPSW that iTunes will accept without any tricks (no need to go into pwned DFU mode, no need to start TinyUmbrella TSS server, no need to redirect to Cydia server for blobs)
PARTIAL blobs stitched to any IPSW requires you to go into pwned DFU mode before running iTunes. No need to start TU or use Cydia though.
stitching either FULL or PARTIAL blobs to a CUSTOM IPSW also requires a pwned DFU start before iTunes restores. No need to start TU or use Cydia though.
stitching is NOT yet supported on iPhones (well, at least not tested). Need to work out the baseband part of the restore process.
will eventually support fetching the blobs directly from Cydia instead of a file on your computer

Download Redsn0w 0.9.9b1 [Windows]
Download Redsn0w 0.9.9b1 [Mac]
Source- redmondpie