ISOBuddy converts and burns disc images -- including DMG, MDF, PDI, and more
It's a disc image conversion and burning program, and it supports more formats than you can shake a spindle at. Apart from more run-of-the-mill formats like Nero's .NRG, .BIN, and .ISO files, ISOBuddy can also handle images created by apps such as Alcohol 120%, CloneCD, DiscJuggler (Dreamcast flashaback... ), and even older Blindwrite files. You can convert from one format to another or burn any supported format to a disc.
As if that's not enough, it can even convert Mac's .DMG format. That's an awesome bonus for me, since there have been a couple occasions where I've been without Mac hardware and needed to get at the contents of a .DMG for a customer. You can convert from one format to another or burn any supported format to a disc.
ISOBuddy is a free download, and it ran nicely on both my 32 and 64-bit Windows 7 systems.