Given that i wouldn't want her to be doing a lot of big downloads if that exceeds data allowances, what in laymans terms is the benefit of 3GS over 3G
Not very much to be quite honest!
3 meg camera Vs 2 meg
Video Camera
Voice Control
Compass
Slightly quicker browsing
That's it! personally, the only thing I'd be interested in is the quicker browsing, but it's never going to make any difference when compared with any laptop or PC.
Personally I was more than happy with my original 2G iPhone, the only reason I upgraded was cos when they brought out the 3G iPhone they offered a FREE upgrade to those of us with an original 2G iPhone, so I thought it silly not to take them up on the offer… Sold my original iPhone for £222 on ebay, so was more than £200 up on the deal all said and done! But 95% of the time I use my phone for emailing or the internet, I'm in range of a wifi network, so the 3G facility really makes very little difference for me. The 3GS version would be even less of an improvement for me, hence I don't think I'll be upgrading when my contract runs out.
And how much storage does a girl need on a phone (given it's probably like a handbag and will be brimmed whatever size it is)
Will she use it as an iPod or not? If yes, then more storage is obviously better as it essentially means you've got more room for storing music. If no, then just buy the smallest version, as otherwise you're wasting your money. Me, I don't have a seperate iPod, so bought the 16GB version as it was the biggest available at the time, 32GB is available now, and rumours are when the next Gen iPhone comes out it will have up to 64GB storage capacity.