Update: Most AT&T stores are out of stock -- if you must have an iPhone today, it looks like an Apple store is the only way to go. Have fun in line!
Update 2: You guys are amazing -- keep those updates coming in! Right now it looks like the best place to nab an iPhone is Brandon Mall, in Tampa, Florida: plenty of stock and only 20 people in line. Who's up for a road trip? So much for that -- see below.
Update 3: It looks like Apple is starting to cap lines so that stores can close by midnight or so. How crazy will it be if there are four hour lines for this thing again tomorrow? Keep those updates coming!
Final update for the night: Apple's capping lines so that most stores can close by 11, or midnight at the latest. We'll do this all again tomorrow, thanks for all your help!
Cube, 4:12pm ET: Line is two to three hours, they don't anticipate running out of stock.
Soho, 7:42pm ET (updated): Lines have been cut off so the store can close later tonight. [Thanks, Jeff]
14th Street, 4:34pm ET: 4 hour (!) line, "plenty of phones," don't think they'll run out, surprised to see that the line hasn't died down.
Apple store on Michigan, 7:34pm ET (updated 3): Line is GROWING (!), approaching 6 hours, Apple still says "we have enough supply to meet the demand." Lines have been cut off for the night so the store can close at midnight. [Thanks, Dan and Neil]
AT&T on State:
Downtown, 4:22pm ET: Two hour line, "Quite possible" it'll run out of stock, in stock right now.
Chandler Apple store, 7:27pm ET: 1+ hour wait, hope to be in stock all night. [Thanks, Mitch -- lowercase letters can be fun, too]
Biltmore Mall, Phoenix, 7:24pm ET: 3.5 hour wait, all models in stock. [Thanks, eric]
All 148 Mobistar stores and 30 Apple premium retail stores are out of stock. [Thanks, David.]
Fashion Island, Newport Beach, 6:06pm ET: 5 hour line with plenty of stock. [Thanks, onedollarbill]
Brea Mall, 6:08pm ET: 2 hour line with plenty of stock currently. No guarantee if the phone will be available later on today. [Thanks, Vincent]
Glendale, 7:18pm ET: 3 hour wait, 250+ in line. No word on stock. [Thanks, Adam]
Beverly Center, Los Angeles, 7:29pm ET: 2-3 hour wait. Plenty of stock. Staff anticipates the same tomorrow. [Thanks, Brad]
Manhattan Beach, 7:58pm ET: 5-8 hour line (!), plenty of stock. [Thanks, Emery]
Sacramento: All models in stock [Thanks, Tom]
Stoneridge Mall, Pleasanton 9:47pm ET: "Quite a bit" of stock. Expected to be open until 10 PM. Line is about 2 hours. [Thanks, Richard]
Rogers flagship in Montreal: Sold out.
Rogers in Toronto: Sold out. [Thanks, Jonathan]
Quebec (city), Quebec (province), 4:54pm ET: Sold out about everywhere of 16GB, but most still have 8GB. Called at least 12 places. [Thanks, blirette]
Regina, Saskatchewan: Sold out in 30 minutes. [Thanks, Chris]
Westfarms Mall, Farmington, 6:39pm ET: Stocked. 30-45 minute line. [Thanks, jhemming]
Sold out by 1pm. [Thanks, Jakob]
5:05pm ET: O2 and Carphone Warehouse both mostly sold out. [Thanks, Hugo]
Brandon Mall, Tampa, 8:00pm ET (updated): One hour line, only 16GB white models in stock. [Thanks, Mauro and Jake]
Jacksonville, 6:47PM ET: 1-2 hour line, still has stock. [Thanks, Corey]
Lenox Mall, Atlanta, 6:36pm ET (updated): 6 hour wait, 250 people in line. Guaranteed to get an iPhone today if in line now. All local AT&T stores are out of stock, but there will be stock at 9:00am tomorrow. [Thanks, Patrick and Benjamin]
5:59pm ET: Most T-mobile stores only had 3 phones each, out of stock all over the country. [Thanks, Jan]
Northbrook Apple store, 7:36pm ET (updated): Two hour wait, no word on stock. [Thanks, Neil]
Old Orchard Apple store, 2:15pm ET: 100+ people in line, still in stock.
Oakbrook Apple store, 7pm ET (updated): Two hour line, "plenty" in stock. [Thanks, Chris]
Woodfield Apple Store, 5:24pm ET: Over 100 people in line, no word on stock. [Thanks, Eric V.]
Keystone Mall, Indianapolis: Sold out at 6pm of 16GB black. [Thanks, Jason -- what's the line like?]
O2 is sold out, very few in Carphone Warehouses. [Thanks, Conan]
Towson Mall, Baltimore, 7:23pm ET (updated): 5-6 hour line (!), probably enough stock for tonight. [Thanks, Don]
Boston Apple store, 5:59pm ET: Perhaps 150 people in line, no word on stock [Thanks, Morgan]
Sold out in most big cities in Mexico (Mexico City, Guadalajara, Monterrey, Queretaro, Puebla, etc.). More shipments expected in eight days. 16GB models are particularly scarce, with only 8-20 per store. [Thanks, Ed]
All AT&T stores in Southern Mississippi are sold out. [Thanks, Logan]
St. Louis, MO, 5:34pm ET: All ATT stores out by 10am. Both Apple stores are in stock, with 5 hour lines apiece. Word is more people than stock. [Thanks, Omar]
West County Apple store, St. Louis, 7:56pm ET: 1.5 hours line, out of 16GB black. Open till 11 cst. [Thanks, Omar]
Menlo Park, 6:57pm ET: 150 people in line, 5 hour line. Stock expected to run low (but not sure if "out") before
the end of the night. [Thanks, George]
Short Hills, 7:20pm ET: 2 hour wait and enough stock for the night. [Thanks, Ryan]
Uptown Apple store, 7:16pm ET: One hour line, 16GB black is out of stock, not sure how long remaining stock will last. [Thanks, DizzyD]
Eastview Mall Apple store, 4:45pm ET: One hour line, out of 16GB phones, "limited" 8GB left, those at end of line likely won't get one. [Thanks, zak]
Crabtree Valley Mall, Raleigh, 5:05pm ET: 300 - 400 deep, 3-4 hour wait, "might" have enough for tonight.
Southpoint in Durham, 5:05pm ET: 200 - 300 in line, 2 - 3 hour wait, should have enough for those in line right now, but could sell out tonight.
Netcom sold out online stock in 60 seconds. All retailers out of stock, with new supplies due Wednesday (online) and/or Thursday in retail stores. [Thanks, Per-Olav]
King of Prussia, Philadelphia 6:47pm ET: 2-3 hour line, plenty of stock.
Ardmore, Philadelphia 7:38pm ET (updated): 2-3 hour line, plenty of stock. [Thanks, Ryan and Michael]
All stores ran out of stock well before noon. [Thanks, Stefff]
Nashvile Apple Store, 7:45pm ET (updated): 4 hour wait, 250 people in line, plenty in stock. [Thanks, Josh and Ryon]
The Domain, Austin, 5:35pm ET: 3 hour line, but plenty of stock. [Thanks, ttrentham]
Highland Park, Dallas, 7:58pm ET: 2 hour wait, plenty of stock. Closing at 11pm. [Thanks, Kenneth]
Salt Lake City, 8:07PM ET: First Apple store to go out of stock. [Thanks, Ethan]
Clarendon Mall and Pentagon City, Arlington, 6:25pm ET: both stores have had a 2.5-3 hour line basically all day; neither anticipates running out of stock this weekend. [Thanks, Matthew]
Tyson's Corner, 5:30pm ET: 6 hour line, plenty of stock [Thanks, Andy]
Bellevue Square, 8:00pm ET: in stock, 2-4 hour wait
University Village, 8:00pm ET: in stock, 2-3 hour wait [Thanks, David]