Ext2 utility "e2cp" alternative for OS X
To the best of my knowledge, you've got two options to mount ext2/3 filesystems in OS X:


fuse-ext2 plugin for Fuse for OS X: open-source projects that appear to be fairly active.
ExtFS for Mac OS X by Paragon: Currently $20 with a free 10 day trial; their page is a little confusing referencing "ExtFS for Mac® 9", which appears to be the version 9 iteration of their product, not Mac OS 9.