iPhone Multitasking

I am almost certainly going to purchase the 3G iphone but I am a little confused as to the iphones abiliy to multitask. For example:

1. If I have fring running for data calls/IM etc, can I be using safari/itunes etc at the same time? Will fring run in the background and alert me when I have an IM?

2. If I am using the maps to navigate somewhere and I get a call, can I still use the map, or does this disappear or shut down for the duration of the call?

3. Can I have an IM client running and read a document etc while waiting for a response?

Thanks for any help here.

The iphone won't allow third party apps to run in the background. But if the IM app makes use of the "push" abilities then when you receive an IM you will get an alert in the same way as you get an SMS or Email alert.
You will then have to come out of whatever you are doing and run the IM program to read and reply to the message.

have you not watched the video from WWDC they say on there that you will be able to have push IM... and be able to have the the IM off and it will push it to let you know you have a message and you will have to sign in and check it.

http://events.apple.com.edgesuite.net/0806wdt546x/event/index.html

check it out. i have verizon but i want a new Iphone.