Greenpois0n RC5 now allows you to jailbreak iOS 4.2.1 untethered on most devices including iPhone 4 and iPad. The best part? You won't need any SHSH blobs saved. redsn0w beta required you to have 4.2b3 blobs saved (and it was pretty unstable). Hopefully greenpois0n is going to be a much smoother experience for you guys. Hit the jump for a walkthrough on how to jailbreak iOS 4.2.1 with greenpois0n and for the answers to some commonly asked questions.

What devices will greenpois0n RC5 jailbreak?

• iPhone 4/3GS
• iPad
• iPod Touch 2G/3G/4G
• AppleTV second generation

You'll need to be running iOS 4.2.1 in order for this version of greenpois0n to work (4.1.1 for AppleTV second generation users).

Should I do a full stock restore first?

In short, most likely. If you're already stock and haven't been jailbroken, you're fine. Still back up your phone first in case anything goes wrong.

If you are currently jailbroken on 4.1, yes. Do a full stock restore to 4.2.1 and restore as a new iPhone. After jailbreaking, I still don't recommend restoring from a backup. Old jailbreak pieces can come with your backup and cause issues for you. Just my personal recommendation.

If you are currently tethered on 4.2.1 via redsn0w, you should be able to just run greepois0n right over your current jailbreak to untether. Some of the devs are saying if you have issues installing Cydia via greenpois0n after running it, simply run redsn0w again and let it re-install Cydia. Basically, as long as you aren't running a Monte version jailbreak on 4.2.1, you should be able to run greenpois0n to untether.

Will this jailbreak iOS 4.3 beta?

No. You'll have to wait a bit longer on a tested jailbreak for 4.3.

Jailbreaking iOS 4.2.1 via Greenpois0n

1. Download greenpois0n onto your Mac. (Some users have been reporting the servers being down. If you can't get it to download right away, just be patient. Their servers are probably just lagging from all the traffic. There are a few mirrors out there so be sure to check the comments for the latest updates on those.
2. Plug your iPhone, iPod Touch, iPad, or AppleTV in via USB (make sure the power is off) and follow the on-screen instructions to enter DFU mode.

3. Greenpois0n will recognize when your phone is properly in DFU mode and start to do its thing. After it's done, you'll see a Loader icon on your homescreen. Tap it and install Cydia. (Note: This only differs for AppleTV jailbreakers. You'll be done but need to continue accessing and installing apps via Terminal and SSH.)

4. You're done! Restore all your stuff (if you choose to or were stock before) and enjoy being jailbroken!

Note: Some users in the comments have been reporting sometimes the initializing error is a result of not holding the home button long enough when entering DFU mode. Even when the text is not greyed out anymore, continue holding the home button if you're getting the Initializing error even after trying Greenpois0n RC5 version 2.

If you guys have already used this version of greenpois0n, let us know how it's going in the comments! Have other questions? Check our our Jailbreak Starters Guide and jailbreak forums!

If you have any questions about the Verizon iPhone 4 announcement today, Verizon is ready to give your some answers via their just-published FAQ. Topics include eligibility, pricing, and international roaming:

customers can use iPhone for voice and text in over 40 countries with data service in over 20 countries. For service availability and rate information, visit International Roaming Rates and Coverage. When travelling outside of these 40 destinations, the Global Travel program is the perfect short-term solution for the occasional or infrequent global traveler who needs to stay in touch when travelling internationally.

Hit the link below for more, and if you still have questions head on over to our Verizon iPhone Forum.

[Verizon iPhone 4 FAQ]

iTunes 8.1 brought us some snazzy improvements to Party Shuffle iTunes DJ and the iPhone's Remote app. That wasn't the only iPhone-related improvement, however, as Ars Techica notes, there's a new feature that used to be reserved for the iPod Shuffle that you can now use for the iPhone: Autofill.

Autofill essentially lets you just fill up the empty space on your iPhone with some randomly chosen music (you can choose to leave some space open for installing apps and the like later on). As somebody who's not really into constantly creating playlists and managing albums, it's a nice option. A nice option that's squirreled away in a pretty difficult to find place.

After the break, we walk you through the steps (courtesy of the Ars Article) screenshot-by-screenshot.

Step 1: Set iTunes to manually manage your music on the iPhone

In the "Summary" tab for the iPhone, check "Manually manage music and videos." This shouldn't erase any of the previously-auto-synced music, but it will mean that your previous auto-sync settings won't work anymore.

Step 2: Find that darn Autofill button

Now that you can manually manage music on your iPhone, you're free to create playlists on the device, drag and drop albums, the whole shootin' match. Additionally, you can, yes, autofill the sucker. To do all that, just click the little triangle next to the iPhone to get a drop down of all your device playlists. Select the Music section and then you'll see your Autofill settings on the lower-right.

Step 3: Adjust Settings

Before you go ahead and auto-fill, you'll want to take a moment to visit the autofill settings:

The setting for "reserve space for disk use" is a little unclear, as you likely are already using plenty of disk space for your previous video, music, and apps. Adjust as you like to choose how much music you'd like to auto-fill with and then decide whether or not you'd like iTunes to give priority to highly-rated songs. Click ok, click "Autofill" and watch your music fly on into your iPhone.

Following up our Exchange Activesync for the iPhone 2.0 walkthrough, and some FREE/cheap Hosted Exchange solutions for users without Megacorps, here's an official "welcome!" from biggest Megacorp of them all, Microsoft. More specifically, from the Microsoft Exchange Team Blog:

If you've not heard; Apple released iPhone 2.0 today which includes a software update to the existing iPhones in the market (yes, we mentioned it when it was announced as well). We're thrilled to add them to the family of Exchange ActiveSync licensees that enable all sorts of devices to connect to Exchange Server. For those of you that manage Exchange Servers this means you may see some new devices connecting and we wanted to give you a few notes about what to expect.

Via