NOW! :)
Yes, if that "non iPhone" can send an MMS. An iPhone can receive an MMS.
Both the iPhone 3G and the iPhone 3G S support MMS with the 3.0 update.
The 3.0 iPhone update supports MMS, but the service is not yet supported by AT&T. AT&T has announced that it will launch the long-awaited MMS service starting on September 25, 2009.
basically picture messaging
you need to text mms to 1010 and it will be enabled
yes the 4.0 has mms
the iPhone 4s should come standard with self activating mms services once the sim card is placed in the phone if still not working go into settings and switch network data on this enables the phone to communicate with the different servers and retrieve mms's from other people as well as you sending mms
mms (In the text message app) or plug it into your computer - in the folder on the apple iphone camera
Make sure mms is on and you can send pictures by testing.
Technically NO but it is just like it without phone sms mms or 3g connection
No it is not avilable.
You can't add a signature to the iPhone. Hopefully an iOS update will fix this. There is an app available in the AppStore called TextFree which allows you to have signatures.