maybe... but to be honest - it's a guess too... ( ;

"La crema di latte è anche detta panna liquida. Il nome è dovuto un po' alla sua consistenza e un po' alla sua derivazione: è la parte grassa del latte e la si otteneva lasciando quest'ultimo a riposare per mezza giornata (adesso è più frequente frullare il latte per velocizzare ed ottimizzare il lavoro)." Wikipedia
I tend to translate 'crema di latte' as single cream and 'crema di panna' as double cream, though they are really interchangeable.

Crema di latte is literally that – the cream that comes from the milk. You can pour it – and you pour it into your coffee (pouring cream - tho you wouldn't put that on a menu)
When you have an ice cream here – they as you if you want panna on it – this is the stuff that has a more solid consistency ans 'stands up'. My understanding is that this is whipped cream; even though my dictionary points my to panna montata for whipped cream, and I wonder if, over the years and with time pressure ,they've just dropped the 'whipped' part in the ice cream shops (and elsewhere).
http://www.slowtrav.com/italy/caffes/gelato.htm

I am not sure whether you would wish to use such simple sounding terms... however, in Australia, we have three types in the supermarket.
There is "thin cream" which is like a creamy milk and cannot be whipped.
Then there is the one to whip which may be called "thickened cream", "whipping cream" or just "cream".
Then there is "double cream" which is your heavy duty cream that can be scooped out of the tub!!
My guess, after asking my family here too, is that they may be referring to the first two types.

Good luck with it!

I think this is the difference.

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Note added at 37 mins (2008-06-19 08:09:05 GMT)
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panna montata
creme chantilly
According to my dictionary.

Just to put another idea in the melting pot!


http://whatscookingamerica.net/Sauces_Condiments/CreamDefini...
http://www.foodsubs.com/Dairyoth.html

In Italian coffee, the frothy milk on cappuccinos, etc, is often referred to as "steamed milk" - the difference between these two could be that one is steamed milk, whilst the other is whipped (or steamed?) cream, like you might have on a hot chocolate.

I hope to be able to help you... crema di latte or panna is the greasy fraction of milk: technically they are the same thing. In the context of "sweet" recipes as in this case, when they say "panna" they usually mean whipped cream. If this is not the case, in my experience usually a modifier is used:
"panna non montata"
"panna fresca"
or in savoury recipes "panna da cucina"
Anyway if you go in any cafe' and ask for a "caffè con panna" usually you will get a coffee with whipped cream on top

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Note added at 6 hrs (2008-06-19 14:28:42 GMT)
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crema chantilly is actually whipped cream with sugar:
see:http://ricette.leonardo.it/ricetta_crema_chantilly_152.html
in Italy... but elsewhere too - see
http://en.wikipedia.org/wiki/Chantilly_cream

It's probably too late but, if it is an ingredient to put in your coffee and you have already panna as cream, perhaps it is what in America is called half&half, a sort of half milk half cream.