Might get the iPhone next week, but I'm concerned about downloading and playing

[MikeatTalkiPhone]

different media formats. For instance, say someone emails me and says, 'hey, I uploaded an awesome mpeg on Rapidshare, here's the link.' I'm sure I can navigate to Rapidshare via the Safari browser on the Iphone, but can I download the video to the internal memory and then play it???? Likewise, if someone emails me an mp3 to my gmail. Can I download it onto the phone and listen to it? I'm just concerned about that mainly. Also, what kind of embedded media can it play? I know it does YouTube well enough, but does all embedded media have to be flash? What if it's an wmv (I highly doubt Apple would play that) or another format? Sorry for the newbie questions, but want to make sure I have my i's dotted and t's crossed. I'll have to pay through the nose to get out of my Verizon contract and then the obvious cost of the iPhone on top of it and don't want my expectations blown out of the water.

Thanks a ton,

Mike - possible iPhone owner...