Other miscellaneous enhancements include the aforementioned on-the-fly playlist creation; external bluetooth keyboard support (similar to what's in the iPad); Game Center for gamers; Location Services control on a per-app basis; the addition of Bing as a search option; Calendar support for iCal birthdays; support for iBooks, including newly added PDF, notes, bookmarks, and automatic remembering of your spot across multiple devices like iPhones and iPad; new luscious home screen wallpapers that should look stunning on the new iPhone 4's retina Display screen; character count in the SMS app; and finally Internet tethering support from AT&T.
A side note on tethering: Normally, this would be included as a major feature, if not for the fact that it's crippled by AT&T's pricing structure, or the fact that this feature has been out for more than a year for iPhones on better carriers. Thanks, AT&T.
Hundreds of new APIs for developers
While I've focused here mainly on user-facing features that arrive with iOS 4, there are hundreds of back-end improvements that will allow developers to produce even better apps for both the iPhone and the iPad. Just a few examples of features developers can add to their apps include: iPod remote control accessories; in-app SMS messaging; spell check; photo library access; Quick Look for document viewing; full map overlays; access to still and video camera data; access to date and address data detectors; and access to Calendar data.
In other words, if you appreciate the breadth and depth of the still-growing number of applications in the App Store, you can expect them to get better as developers adopt these new functions and add them into their apps.
iOS 4 offers a number of compelling reasons for users to upgrade, featuring performance and app enhancements that are well worth the price. That price? Free for all of the hardware that can run it (even for the iPod touch). Upgrading should be simple: Plug your iPhone or iPod touch into your Mac, launch iTunes, and click Check for new software. Follow the prompts and you'll soon be ready to see for yourself.
Is iOS 4 the pinnacle of smartphone technology? Of course not; there is still much room for improvement. (For starters, an organized notification screen for alerts would be really useful.) But the new features and tweaks in this update -- in concert with the fact that Apple is giving the software away -- make this upgrade a no-brainer.
Michael deAgonia, a frequent contributor to Computerworld, is an award-winning writer, computer consultant and technologist who has been using Macs and working on them professionally since 1993. Find him on Twitter @mdeagonia).