Difference betwwen iPhone 3G and iPod Touch?

Besides the lack of all the phone functionality, the iPod Touch lacks the camera as well.  Besides that, it still runs the majority of the apps while being a bit smaller and thinner.  It just kind of depends if you need all that functionality in a media player.

Also, the iPod touch comes in a higher capacity model.... largest iPhone 3G is 16GB, the largest touch is 32GB. If you have a lot of music, it's something to consider. 

I think it just depends on whether or not you want everything in one device. If you don't mind carrying around your phone along with the touch, then it's the better option.

That was definitely an appealing aspect of the iPhone for me, when I last went phone shopping.  At the time, I was carrying a phone and an MP3 player in my pockets during my walk to the office. The idea of being able to ditch the MP3 player, and just use my phone was pretty exciting. 

Turns out the phone I went with, the Moto Q isn't a great MP3 player though:

• it doesn't have a built in headphone jack (instead it uses a micro-USB dongle, which I lost within a few weeks),
• it has no built in EQ, so playback sounds pretty flat,
• while it supports microSD cards up to 4 gig, putting files on it takes about an hour per gig, and 4 gig just isn't that much storage.

Long story short, if you want good MP3 playback and cellphone capabilities in one device, the iPhone is a great way to go.

I'm glad more and more phones are starting to feature a real 3.5mm jack.  Dongles for wired stereo headphones are so annoying.  And 2.5mm jacks are much less useful than they used to be.  Bluetooth headsets for talking have come a lot farther than Bluetooth headsets for music listening in my experience.

they  almost have the same founction, maybe a little difference in capicity , other thing I don't know !