The highest memory you can get is 32GB
32GB.
No, you can not upgrade your iPhone 3G memory.
There's no such thing. The iphone does not have a memory chip you can plug in. If you mean internal spare parts then ebay.
As many as you have memory for when u plug in your iphone to your computer, open itunes and on the left under "devices" your iphone should be there. Click that and look at the bottom of itunes and there will be a little bar that gets full when your memory is getting full. If it is white for most of the bar, you should be good for a while. Most apps aren't huge.
There are no memory cards available for the Iphone so you will not void the warranty.
Unless you delete stuff on your iPhone, you can't add memory to the iPhone. This means if you're looking to buy an iPhone and you're going to store lots on it get big memory like 16 or 32GB. Hope this helps!
no
Is there enough internal memory on your iPhone??
No.
no you cleary can't
balls