iPhoto launches by default when you plug in a digital camera. The iPhone counts.
If it’s your only camera, or you don’t mind launching iPhoto automatically when you plug in a “real” digital camera, you can turn off the preference for iPhoto. I don’t think you do it in iPhoto itself, but in one if the applications in the Applications/Utilities folder. (“Camera options” or something? I’m not at my mac at the moment.)
OK, now I am next to my Mac. You want the “Image Capture” application in your Applications folder. In Preferences:General, there’s an option for what to do when a camera is connected. Set it to “No application.”
Ah HA! Thank you! That’s been bugging me.
I have a logitech mm50 speaker set I bought for my iPod, and it works perfectly (though not quite as loud) with iTunes and youtube on my iPhone. I haven’t checked max volume on the iPhone yet, but even at the present volume it’s cool.
I’m thinking the iPhone will also work on an adapted stereo in my car. Something I haven’t gotten around to getting yet.
Now I need to find a dock-to-dock cable so I can play it in horizontal.
Peace,
mangeorge
Take the iPhone with you when you do, so you can check the connection. The headphone connector is recessed, and even though most of my headphones LOOK like they fit tightly, not one of the eight pairs I tried could actually connect to it.
A couple minutes with a penknife whittled down the connections so they’d fit, but that might not be something you want to do to brand new headphones/adaptors (my car cassette adaptor needed the same treatment.)
Alternatively, there are several companies making adaptors (extenders, really) to solve this problem, but my local store didn’t have any yet.
The iPhone supports stereo bluetooth technology, but Apple’s not turned it on yet. Look for this to be changed in an update some time in the near future, so you might be able to connect your phone to your stereo via bluetooth. 
The car, I don’t think will be a problem. Thanks.
The speakers though, like most others I’ve seen, have a dock connecter like on the cable you use to sync with your computer. Problem is, it holds the iPhone vertical. I’d like to get a cable with the dock connector (opposite sex) on each end, so I cound prop my iPhone horizontal for videos and youtube, etc. There are holsters available with snap-out,props for both vert. and horiz.
Picky, huh? 