Apple’s Steve Jobs appeared on stage today to say that the company has sold 30 million iPhones to date. Later in the presentation, SVP of product marketing Philip Schiller confirmed that they have sold 20 million iPod Touches. That’s a total of 50 million devices that have access to the iTunes App Store, which has more than 75,000 applications. In all, users have downloaded 1.8 billion applications from Apple.

Schiller took the opportunity to knock the competition when it comes to gaming and entertainment titles on the iPhone OS compared to the Sony PSP and Nintendo DS. Schiller said the PSP has 607 titles, the Nintendo DS has 3,680 titles and the iPhone has an overwhelming 21,178.

The number of iPhone and iPod device users are still a fraction of Apple’s overall iTunes users. Today, Job said iTunes is now in 23 countries and that there’s 100 million accounts that are connected to credit cards.

With scale rapidly making the iPhone and iPod Touch one of developers’ favorite platforms to build applications for, the next conundrum is merchandising. With the new iPhone and iPod Touch 3.1 software upgrade, Apple has made that even better. Now in addition to such App Store categories as “New” and “What’s hot,” there’s a new category called “Genius.” It uses the same technology that delivers song recommendations to people in iTunes, but it gives app recommendations based on what you have previously downloaded. For instance, if you liked a golf app, then maybe EA’s Madden would also appeals to you.