iPhone OS 4.0 is already readily available over the internet. Somewhat less than honorable “developers” are even offering to “sell” access to the 4.0 beta. This has led to a lot of users getting, or at least thinking about getting, the 4.0 beta for their own iPhones (it's currently not even loading on iPod touches -- and forcing complete restores for recovery, so don't even consider that at the moment!). Well before you take the jump think carefully. And think twice!

Read more after the break!

This is not finished software. This is a beta, and not in the Google/Gmail perpetual meaningless beta sense. This is a true beta in that it is not meant for production iPhones, used as primary devices, out in the real world. Who knows what kind of de-bug, trace, non-optimized, or generally not finished code is running in the current, and first iPhone OS 4.0 beta. If you’re a legitimate developer, using 4.0 on a test device to check for compatibility for your apps and report bugs back to Apple is one thing. To think you can use it for regular, day-to-day use is quite another.

First kiss iTunes backups goodbye and don't expect working multitasking as no 3rd party apps have been updated to support it. 4.0 may be slow. Lists may disappear. Sound may cut out. Connection may time out. Battery time may worsen. 3rd party apps may crash or otherwise not work well. And you may need to reset your iPhone daily, if not several times a day, to work around the beta nature of the current build. You get the idea and that’s what happens with a real beta.

Also, these beta’s expire, and if you don’t have quick access to the next beta, you’ll be without your iPhone — and that’s assuming Apple doesn’t wait hours or days between expiry and the next beta release. And dropping back down to the previous build isn’t always easy or possible.

So, yes, iPhone OS 4.0 has lots of amazing features, and we hope very much it will be killer stable come “summer”-time when Apple releases it via iTunes for everyone. Until then, read our iPhone 4.0 coverage. Watch Apple’s video. If you’re not into testing pre-release software, if you’re not patient, if you need a reliable, primary iPhone, if you want it to “just work” think twice before loading the iPhone 4.0 beta. Then think again. One look at our developer forum shows it isn’t a smooth ride.

(And tech pundits who’ve told readers and listeners it’s no big deal, and to go for it, should also think twice and remember they’re often cutting edge users themselves, with many devices to fall back on — not the case for everyone.)