ext2 driver for Windows
I had previously used ext2fsd, but that was quite a pain to set up. This has a nice installer and lets you map your Linux drive right to a drive letter in Windows because it is a full kernel-mode file system driver (Installable File System driver). It supports read/write too. Doesn't support any security on the drive so caveat emptor.
It doesn't support any partitions using volume management either (not a surprise).
Ext2 IFS For Windows
provides Windows NT4.0/2000/XP/2003 with full access to Linux Ext2 volumes (read access and write access). This may be useful if you have installed both Windows and Linux as a dual boot environment on your computer.