How to: pre-order the iPhone 4 (update: third-party retailers best avoided)

It's now less than twenty-four hours until pre-orders for the iPhone 4 kick off, magic is in the air, and you're feeling good -- but where (and how) do you get your name in the system? There'd be nothing more tragic than waking up on the 24th only to discover that your phone isn't arriving on launch day, so let's get things squared away right now so you know what you need to do tomorrow morning.

Follow the break for everything you need to know!

The most painless way (most likely) will be to pre-order online from the comfort of your home at Apple's site, because you'll be guaranteed delivery on launch day without any hassles of dealing with lines, riots, or uninformed sales clerks. The big question is when exactly the pre-orders will go live, and at this point, no one knows for sure. In all likelihood, it'll happen after the typical "we'll be back soon" outage, but it's unclear whether that'll happen around midnight or tomorrow morning during business hours. Our advice is to hold out until after midnight Eastern tonight, but if you're not at least greeted with "we'll be back soon," hit the sack and get up early. For comparison, iPad pre-orders kicked off at 5:30AM Pacific Time, so we wouldn't be surprised to see the iPhone 4 do the same. You can go into a physical Apple Store if you really want to, but we're being told that you'll just be directed to a computer to go through Apple's website anyway, so there's really no point.

You'll also be able to pre-order in AT&T stores tomorrow, but as far as we can tell, this is going to be a pretty unsavory option -- you'll be required to have your credit card authorized for the full amount upfront, and according to the locations we contacted, you won't even be guaranteed availability on launch day; instead, you'll need to wait until the 25th for some bizarre reason. AT&T's website seems to be a better option, with June 24 delivery available to both consumer and business customers. The carrier won't disclose to us what time pre-orders will start, so keep an eye out.

Major third-party retailers will be getting in on the action, too:

• RadioShack will be accepting pre-orders in stores for a $50 deposit, which will come off the price of the phone when you pick it up; they're throwing in an accessory credit, too (basically the same setup as the EVO 4G launch). Stores will be opening at their normal times tomorrow, but some locations will be opening early on launch day.

• Best Buy is the same deal, basically -- $50 deposit taken in-store at the regular opening time, with most locations opening early on launch day.

• Walmart seems to be pretty clueless about the situation; though they're confirmed for a June 24 launch, we weren't able to find any sales clerks at any of the locations we contacted that knew how, or if, pre-orders would be taken tomorrow (two didn't even know there was a new iPhone, and instead insisted we were referring to the $97 deal on the 3GS). Bottom line: only get in touch with these guys tomorrow as an absolute last resort.

So, what's everyone's game plan?

Update: It seems there's been a last-minute change in plans at some RadioShacks -- pre-orders will no longer require a $50 deposit, and some locations will be opening early in the morning. Our advice? Check with your local store right now.

Update 2: We've been tipped that Apple may now be blocking third-party retailers from taking pre-orders altogether tomorrow. RadioShack already changed its story on us, and now Best Buy locations have started doing the same, telling us that they definitely won't be taking pre-orders tomorrow but may be by the end of the week. Bottom line -- hit up Apple's website in the morning.

Update 3: Some folks are being told that pre-orders are still on for tomorrow at Best Buy; that doesn't seem to be the case at the three stores we've called, so your mileage may vary. If we had to guess, this is just a case of extraordinarily poor employee communication. We'd still avoid hitting up a third-party retailer for the pre-order if possible -- it just seems to be too chaotic at the moment.