Steve Jobs enters the stage wearing his standard uniform of jeans and a mock black turtleneck. He thanks everyone for coming—all 5,200 attendees, which is Apple’s (NSDQ: AAPL) first sold-out event. (Video is here, on the Apple website.)

Jobs first addresses the iPhone 2.0 platform. “We started the developer program on March 6, just 95 days ago, we had 250,000 people download the free sdk. We had 25,000 apply to the paid developer program, and we couldn’t take everyone, so we admitted 4,000 to the program.” There’s three parts to the software: Enterprise support, the SDK, and end-user features.

On Enterprise: 35 percent of the fortune 500 has participated in the enterprise tests. “Not so bad,” Jobs says to an applauding crowd. There’s a video on how Disney (NYSE: DIS) has been testing the beta release, and said they have deployed seven applications.

On the SDK: Scott Forstall comes on to the stage: We are opening up the same tools internally to build all the apps that ship as the iPhone. You as a developer can build applications the same way we do. We have a great set of APIs, on top of this we have a really powerful set of tools. Xcode is what you’ll use to build and debug your code. Interface Builder will let you construct your interface and connect to your code. iPhone simulator to run it on your Mac. And, the last tool is instruments, a full suite of tools. There’s a demo of him creating an app for the iPhone using location tools to find out which of your contacts are nearby. This looks pretty easy with lots of drag and drop standard features, like a search bar.

Now there’s a few demos by developers who have been using the SDK:

Sega: Ethan Einhorn says in March they showed four stages of Super Monkey Ball and soon after, they completed 110 stages. In a demo, they are showing the last world where a monkey in a bubble collects bananas, which requires “pinpoint control.” The tilt control works beautifully, he says. It will be available for $9.99 with the launch of the app store.

eBay: Ken Sun is showing off auctions on the iPhone. “Five weeks ago, we decided to create this application.” The homescreen has a search bar, so they demonstrate searching for the Wii Fit. There’s a Web kit added, so you can see the seller’s description and the items you have bid on. Enter the bid amount, confirm it and it’s entered in the system. On the watch list is a multi-million house, which demonstrates how easily you can see the pictures. The app will be free.

Loopt: Sam Altman demonstrates the location-based service. There’s a map with pinpoints of where your friends are. “We’ve developed for nearly every mobile platform out there, and this is the best.” Tap on one of your friends to see where they are, and then you can call or send a message. The app will be free.

TypePad: The blogging software makes mobile blogging easy. Three options from the homescreen: Create a post, take a photo, or add a photo. You can choose a photo you want to upload, choose the blog you want to post it to, and then you can add a message. Once sent, you get an alert to know that the post has been created, which can take you to Safari to see that it’s been uploaded. The app will be free.

AP: They are building a native application, building off the one available for Safari. Benjamin Mosse says the iPhone has been an important catalyst for getting local news to the mobile phone. The Mobile News Network is where you can add several locations to get local news. But the iPhone now knows where you are automatically. The news caches so you can read it on a plane or when you are out of network. You can watch video, or view pictures of the news. You can share the news by text or email. And, there’s a citizen journalism component where you can upload news you witness. “Hands down it’s the most feature rich platform going.” It will be a free app.

Moo Cow Music: Mark Terry, a developer in the insurance industry in England, has been developing stuff for the iPhone in his spare time. The app lets people create music on the iPhone from scratch. There’s a mini piano, a blues interface and something called funky drummer. By far, he gets the biggest crowd support, by playing the blues, and the bass guitar and drumming.

MLB.com: This app features all the game scores, but the cool thing is real-time highlights. The quality “made it an easy decision” to feature video highlights. They come minutes after the play, not after the game.

Modality: A third of physician who plan to buy a phone in the next few months, said they were going to buy an iPhone. Mark Williams is demonstrating a learning app that replaces flashcards. The app features different parts of the body and then there’s detailed images of various body parts, like a heart. He says: “imagine doing this on any other mobile device,” which prompts one audience member to laugh loudly, causing the entire crowd to break down. We’ll have a dozen apps available within weeks of the app store launch.

MIMvista: Mark Cain says it’s hard to be caught without a desktop computer, but with this app you can see Cat scans and thermal data. You can see a scan from the bottom, side or front. After one week, there was a prototype. You can measure body parts by drawing a line; the line is erased when the phone is shaken. “The iPhone has created a new direction for our company.”

• @ WWDC: One Hour And Counting Before Apple Keynote