I'm using TransMac
http://www.asy.com/scrtm.htm

# Read and write Mac format disks, CDs, DVDs, high density floppies and disk images (dmg and sparseimage).
# Supports standard HFS (Mac OS Standard), HFS+ (Mac OS Extended) and HFSX (with case sensitive file names) volumes.
# Access Mac volumes on boot drive (like Boot Camp).
# Create, read and write Mac disk images (dmg and sparseimage).
# Compress and expand (convert to iso) dmg files.
# Built in burner software to create Mac format CDs and DVDs (including dual-layer).
# Burn ISO and dmg files to CD/DVD.
# Format disks for use on Mac.
# Read Mac multisession and hybrid CDs.