In another valiant and heretofore unsung effort to free itself from the shackles of whose, English has produced one more revolutionary in the person of Ben Wenet, who on August 22nd, 2008, was observed to state:
"I have a friend that's mom lives there too, so..."
This is largely the same strategy we saw with Micole Arny, except that she chose what's as the relative pronoun instead of that's. The thing that I find particularly remarkable about this, though, is that the possessor in this clause is animate -- I would have expected a whose to slip out much more easily in this type of situation than when the possessor is inanimate as in Micole's example.
I have a theory: it could be bunnies. OR, perhaps less controversially, that whose is being increasingly considered to have been pushed into a register where it feels inappropriately formal outside of a literary context. It seems obvious to me that users of English are desperately searching for something to replace it with, and trying all kinds of different options (all of which are perfectly reasonable from a cross-linguistic perspective, it might be worthwhile to note). Two other strategies that I haven't commented on yet throw away the relative pronoun (and gap) entirely: my mother's, e.g...
"...houses that their insulation isn't thick enough..."
And, embarrassing though it is to have to admit him to the vanguard of linguistic change, John McCain's, at least on September 26th, 2008:
"We have a defense system that the costs are completely out of control."
I don't know that we have enough data to start making conclusions yet, but this much is clear to me: something is on the move here.