That's right. some carriers also do not support MMS. If that is the case, you can't send your videos or photos. But that's a limit of your carrier, not the iPhone 3G S
Yeah, I think that it is possible to send pictures and videos. I think that there's a limit for the your "Attachment" though. If you already have one, look through the manual maybe?
ya you cans end it via MMS ,Take a photo or shoot some video, then send it via Messages. You can
also send audio recordings from Voice Memos, contact information from
Contacts, and locations from Maps.