So after a good 6 weeks, I’ve discovered what I consider to be the first killer app on the iPhone. Software available from SimplyMedia allows for some of the most useful functionality I’ve found to date

Basically, it allows you to stream your iTunes library (or any other music files on your computer) to your phone via the Wi-Fi, EDGE, or 3G connection on your iPhone. It took a while for that to sink in for me, but I was really impressed when the lightbulb went off. Basically, I no longer have storage concerns with the iPhone. 8 GB is plenty for apps and pictures, and with this software, I can have access to all of the music my PC can hold. I’ve been playing with it for a few days and I must say it works well even on EDGE speeds. When streaming iTunes music from your PC, the software gives you all the same functionality as the phone’s iPod function except for the CoverFlow album art.

What’s even crazier, is that it allows you to share your library with up to 30 friends. That’s right, if I had 30 friends, I could have access to all of their music libraries via my phone.

The iPhone app is going for $3.99 and the client for your PC is a free download. The real question is how long will this last in the app store? Are Apple and/or the RIAA gonna be big fans of this in the long term? Also, how long until the BB and WinMo crowds start clamoring for this same type thing, or does it already exist and I’m just a lame, biased, and totally unaware iPhone user?