We could put our hands on an iPod Touch, and quickly compare it with the iPhone.
The iPod Touch is slightly smaller than the iPhone in size, but massively thinner. Despite cosmetic points, the high-end iPod does exactly the same things than the iPhone, mobile phone ability on the side. If the iPod Touch can not be used to edit calendar entries, this is only because Apple decided it, whereas it should be feasible without any problem.
For sure the iPod Touch is the best iPod ever designed and manufactured. With the future price decrease of NAND memory, future versions with larger storage space will be released, bringing capacity to 32 or even 64 GB, and burying at that time the iPod Classic.
Currently, the iPod Touch is stacked between the iPod Classic and its larger storage space, and the iPhone and its smaller capacity (8 GB). So iPod Touch or iPhone? If you can not imagine having a mobile phone without 3G support, or a digital music player with only 8 GB storage space, than buy an iPod Touch, otherwise, go for the iPhone.
Of course, in most countries, such choice is not really possible, as the iPhone is still limited to USA, if we do not consider the grey market...
[translation by Linathael]