Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
You can set iPhone to play a sound whenever you:
ÂÂ Get a call
ÂÂ Get a text message
ÂÂ Get a voicemail message
ÂÂ Get an email message
ÂÂ Send an email message
 Have an appointment that you’ve set up to alert you
ÂÂ Lock iPhone
ÂÂ Type using the keyboard

Taken from the iPhone manual I downloaded from Apple.com ;)
 
You can set iPhone to play a sound whenever you:
ÂÂ Get a call
ÂÂ Get a text message
ÂÂ Get a voicemail message
ÂÂ Get an email message
ÂÂ Send an email message
 Have an appointment that you’ve set up to alert you
ÂÂ Lock iPhone
ÂÂ Type using the keyboard

Taken from the iPhone manual I downloaded from Apple.com ;)

yes but the problem is that apple will let you turn these on or off, but they will not let you change the sounds..
 
You can set iPhone to play a sound whenever you:
ÂÂ Get a call
ÂÂ Get a text message
ÂÂ Get a voicemail message
ÂÂ Get an email message
ÂÂ Send an email message
 Have an appointment that you’ve set up to alert you
ÂÂ Lock iPhone
ÂÂ Type using the keyboard

Taken from the iPhone manual I downloaded from Apple.com ;)

Yes but the question is which sound it plays. I haven't seen where you can use custom sounds for any of these.
 
It's completely possible...but only if you've jailbroken. Apple has kept the 6 SMS alerts hardcoded for some reason. You can't even add extra ones, you have to actually replace the old ones (the hackers may have fixed this by now). This could be a measure to keep people from having those annoyingly long song text alerts, something I could see Steve being testy about.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.