iDector is a real easy to use application to tell wheter or not your
iPhone 3G[S] contains the New Bootrom or the Old bootrom.
Simply place your 3GS into DFU mode and click the button.

Devices Supported:
* iPhone 3G[S]
Download: Here
The iPhone Dev-Team has released a new version of UltraSn0w which can unlock iOS 4.0.
iPhone DevTeam's 3G and 3GS software unlock, now with added PwnApple. Compatible with basebands 04.26.08, 05.11.07, 05.12.01 and 05.13.04! Thanks to @sherif_hashim and @Oranav for contributing baseband crashes.
You can find instructions on how to install the UltraSn0w unlock here
Note: The iPhone Dev-Team has not yet released the jailbreak utilities for iOS 4. So those who want to update should wait a little bit. Those on 3.1.3 with the 05.12.01 baseband can install UltraSn0w right now to obtain an unlock.
Source:
For detailed procedures on unlocking, click HERE
For procedures on jailbreaking your iPhone click HERE
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all four one!
Around an hour ago the new version of the iPhone Operating System (now called "iOS") was released.
iOS 4 is a huge release for Apple with many many changes and those changes offer slick additional features.
These new features are being offered by Apple as a free upgrade to qualifying devices.
We are working hard on a release to our tools that will jailbreak your device (or give you iOS 4 via the jailbreak train) and provide you with a carrier unlock.
Until these tools are released you should hold off on updating your device until we have fully tested our tools with all the relevant devices.
If you rely on hacktivation or a carrier unlock (ultrasn0w) then you should not upgrade until we have fully tested and released our tools.
Don't be tempted with unofficial PwnageTool/redsn0w bundles or releases, just check here or our team twitter for real time release information.
Remember, we risk our devices so you don't have to (but this time anyone who has made a mistake upgrading their baseband firmware at 3.1.3 or 4.0 should be OK Now!
Source:
Hers is the easy way to install and dual boot iPhone and Android on your iPhone 2G handset. We will bring you the tutorial on dual booting the Android 2.1 on iPhone 3Gs as soon as it will be released.
The installation process involves 5 easy stages which you can quickly finish with a little patience and bandwidth. Get ready here it comes.
Stage 1: Downloads
1. VirtualBox (link). Get the right version Windows/Mac
2. VirtualBox Ubuntu Image (link). Download number 10, Ubuntu Linux 9.10 codename Karmic Koala x86
3. iPhone Explorer (link). If you’re on Linux you can use FTP such as FileZilla instead.
4. Android images and sources (link)
5. Patched images (link). Courtesy of Geekoid.
Stage 2: Landing
1. Open Task Manager
2. Kill the iTunes Helper process
3. Install iPhone Explorer
4. Connect your iPhone to your Mac/PC
5. Run iPhone Explorer
6. Click the Change Root button
7. Select “/” Real iPhone Root Directory
8. Browse to private/var
9. Copy ramdisk.img, userdata.img, cache.img and zImage from Downloads#5 (Android images and sources) to that var directory
10. Copy system.img and android.img.gz from Downloads#6 (patched images) to the that var directory
Stage 3: Configuring The Virtual Box
1. Install VirtualBox
2. Open VirtualBox
3. Go on File > Virtual Media Manager
4. Make sure Hard Disks is selected
5. Click Add
6. Locate the ubuntu-9.10.vdi file (download#3) and select it
7. Close Virtual Media Manager
8. Go on Machine > New
9. Click Next
10. Under Name enter “Ubuntu”
11. Select Linux Operating System
12. Select Ubuntu Version
13. Click Next
14. Set an amount of RAM, the default should be fine
15. Click Next
16. Select “Use existing hard disk”
17. Select the ubuntu-9.10.vdi
18. Click Next
19. Click Finish
20. Select that new machine to start up Ubuntu
21. The password to login is: reverse
Stage 4: Configuring Ubuntu
1. Click System (top bar) > Administration > Synaptic Package Manager
2. Enter the password: reverse
3. In the quicksearch box, type libusb-1.0, click the Check Box next to libusb-1.0-0 and select Mark for installation
4. In the quicksearch box, type libreadline, click the Check Box next to libreadline5 and select Mark for installtion
5. Click Apply
6. When it’s all installed close the Package Manager
7. Open Firefox (in Ubuntu)
8. Download openiboot installer from here
9. Click Places (top bar) > Downloads
10. Right-click openiboot.zip and click Extract Here
11. Click Applications (top bar) > Accessories > Terminal
12. Without the quotes, type ‘cd Downloads/openiboot’
13. Restart your iPhone in Recovery Mode (power off, hold down Home button, connect to USB cable)
Stage 5: Starting Android On Your iPhone and this is the final stage before you can enjoy the dual boot option.
1. In VirtualBox, the Ubuntu Window, go on Devices > USB Devices and select iPhone (Recovery Mode)
2. In the terminal type (without quotes): ’sudo su’
3. Enter the password: reverse
4. In the terminal type ./loadibec openiboot.img3
5. You’ll see the OpeniBoot screen appear on your iPhone
6. Hold down the power button a couple of seconds (iPhone)
7. The bottom option, openiboot console, will become selected
8. Press Home (iPhone). You’ll see a bunch of text appear and stop at “Welcome to openiboot”
9. In VirtualBox, the Ubuntu Window, go on Devices > USB Devices and select iPhone (OpeniBoot Mode)
10. In terminal type su ./oibc
11. Enter the password: reverse
12. If this doesn’t work just type: ./oibc
13. You’ll see the same text from the iPhone in the Terminal
14. Type (without quotes) ‘nor_read 0×09000000 0×0 1048576? and press Enter
15. Wait for it to say Done
16. Type (without quotes) ‘~norbackup.dump:1048576?
17. This creates a backup of your NOR memory – save a copy on USB stick, or email it to yourself or something
18. Type install, press Enter. When this is done you’ve got openiboot installed on your iPhone.
Now that you have got your dual boot you need to finish the process and enter your new Android:
1. if you still have Terminal open with the oibc still running, just type ‘reboot’, press Enter and skip to step 3
2. If you don’t have Terminal open, disconnect your phone, turn it off and back on
3. When openiboot appears press Power button to switch to openiboot console (bottom option)
4. Hold down the Home button
5. Android will start to boot, but it might take a while
Go and show your friends your new iPhone with dual boot.
i already solve this via hardware....
no need flashing.....
solution on image below....


-yaps-