I spoke to a programmer a few months ago who told me that BitCoin isn't really inflation free because people can basically purchase licenses that enable them to create new bitcoins in large amounts. Although they do have to sacrifice computer processing time to create them, there's no way to tell just how much that might limit their "minting." I was actually sort of interested in investing in bitcoins before I heard that. The other problem is that although nobody has been able to hack the system so far, you never know if that might change in the future. By contrast, gold cannot be "hacked" into existence by any method known to science.
Fist of Freedom blog