I had a run-in with Vista 64-bit edition today in trying to get some ISOs mounted on my dev machine. All the company media is out on the network as ISOs.
The road blocks stemmed from the fact that the 64 bit version of Vista doesn’t work with most wares I’ve used in the past to mount ISOs as drives.
A quick Googling helped me find, Virtual Clone Drive which comes complete with fancy sheep icons. Nice.
It lets you create multiple virtual drives and then you can easily right-click on the drive (from Explorer/My Computer etc) and mount an ISO.
It handily keeps a recent ISO list so that remounting is easier if you repeated use the same ISOs (true for me as I’m right now configuring a bunch of VHDs for Virtual PC).