If you follow any tech blogs, you have probably seen the news that Apple is hosting an event on Thursday that is billed as “a sneak peek into the future of iPhone OS”. Of course, there is much wild speculation about what this might mean, with predictions of multi-tasking abounding.

First, please stop saying that the iPhone OS does not multi-task. Yes, it does. It has from the beginning. Ever wondered why your phone can check mail and play music and sync your calendars while you are playing a game? Ah, I see the light of realization dawning in your eyes! “But, why can’t I listen to Pandora while I am in Safari then?”, you ask. Simple. The ability to run apps in the background (multi-task), is not available to third party developers.

The non-ability of apps to run in the background has probably been the number one criticized point about the iPhone, and now the iPad. But why is this? Personally, this is not one of the things that really bothers me about the iPhone. It would be nice to have the option to listen to Pandora when doing other things, and to set alarms in my own iPhone app, but it’s not my number one most wanted feature.

My number one, most wanted, must have feature for the iPhone is:

Allow me to set custom sounds for incoming SMS messages!

I follow a lot of people on Twitter. I get literally hundreds of SMS messages every day. Because of this high volume, I keep my phone on silent mode. It would be very, very helpful to be able to set SMS messages from Twitter to vibrate, but messages from other people to use an audio alert. And not just those same old alerts that we have had since OS 1.0. Those have become stale. I want to use my own sounds for SMS alerts.

So Apple, if you are listening, how about it? Can we please get custom, assignable SMS alerts for iPhone OS 4.0? Pretty please?

How about you, readers? What is your number one most wanted feature for the iPhone?