If you are a jailbreak user , you may like to save your SHSH Blobs for future use . SHSH blobs are required for downgrading your firmware . Also TinyUmbrella can be used to preserve baseband while upgrading your firmware .
Read more about How to Save SHSH Blobs .
You can download TinyUmbrella Version 5.0 here . Note that this version will only save your SHSH Blobs . Some problems like “Fix Recovery” needs to be worked upon on iOS 5 , so you can use it for baseband preservation aswell .