I heard from one person who bought a house with their pizza bitcoins, indirectly, by trading it for cash first. Apparently it was a lot of hassle with the bank due to AML and just their general distaste for currencies they don't control. I wish I could say I did the same, but the pizza didn't appreciate the same way as the bitcoins 
I think pizza always appreciates. @Laszlo your pizza sorry was the first story I read about bitcoins and my first knowledge of cryptocurrencies, your a legend.