There is not better feeling then having the only iPhone 4 around my friend running a jailbroken version of iOS 5
Here are the steps I followed to go from iOS 4 to iOS 5 GM :
1) Make a backup of your iPhone 4 using iTunes and and backup that file to somewhere safe. iTunes backups are stored in the C:\Users\YOURNAME\AppData\Roaming\Apple Computer\MobileSync\Backup folder.
I have also seen that lots of people say you need to make an shsh blobs backup to restore to your current version but I would advise against people going to iOS 5 GM if they have important files they don't want to lose.
2) Download yourself a version of iOS5 GM, I torrented mine of thepiratebay.org and also download the beta 7 version of iTunes 10.5
3) By using shift + (click restore in iTunes) select the ispw and restore your iPhone.
4) Download Snowbreeze v2.8b8. (This is the only one that worked for me)
5) After following the instructions inside of snowbreeze you will note that there is now a new ispw file on your desktop and a folder called iBooty. After the jailbreak my iTunes opened up and requested that I restore again, use **** + restore again but this time select the ispw created by snowbreeze from your desktop. Once the process is completed your iPhone will now have cydia on the second homescreen.
6) Inside of cydia you can install all of the previous packages you were using on your previous OS.
7) As this is just a GM and we all want to test it you can make use of iFunbox to install apps on your iPhone.
This guide isn't the most legit one out there but this is what worked for me to get to where I am now. I powered my phone down last night and made use of iBooty to to reboot and all of my apps( cydia etc. ) continued to work.
let me know if this works for you.
thanks to fxit_man and morkhans for helping me out

Here are the steps I followed to go from iOS 4 to iOS 5 GM :
1) Make a backup of your iPhone 4 using iTunes and and backup that file to somewhere safe. iTunes backups are stored in the C:\Users\YOURNAME\AppData\Roaming\Apple Computer\MobileSync\Backup folder.
I have also seen that lots of people say you need to make an shsh blobs backup to restore to your current version but I would advise against people going to iOS 5 GM if they have important files they don't want to lose.
2) Download yourself a version of iOS5 GM, I torrented mine of thepiratebay.org and also download the beta 7 version of iTunes 10.5
3) By using shift + (click restore in iTunes) select the ispw and restore your iPhone.
4) Download Snowbreeze v2.8b8. (This is the only one that worked for me)
5) After following the instructions inside of snowbreeze you will note that there is now a new ispw file on your desktop and a folder called iBooty. After the jailbreak my iTunes opened up and requested that I restore again, use **** + restore again but this time select the ispw created by snowbreeze from your desktop. Once the process is completed your iPhone will now have cydia on the second homescreen.
6) Inside of cydia you can install all of the previous packages you were using on your previous OS.
7) As this is just a GM and we all want to test it you can make use of iFunbox to install apps on your iPhone.
This guide isn't the most legit one out there but this is what worked for me to get to where I am now. I powered my phone down last night and made use of iBooty to to reboot and all of my apps( cydia etc. ) continued to work.
let me know if this works for you.
thanks to fxit_man and morkhans for helping me out