At first I thought, and sorry about this..."this guy must be an idiot, all you do is click the date/size etc to sort"......
Then I actually went to Hotmail, and you are quite right, I hunted high and low, nothing!
Its insane!
I have never noticed this before as I only use mine for paypal and MSN so it never gets past the first page of email messages.
Does this facility appear if you pay for full Hotmail???