Thursby's Dave, for connecting Macs to Windows networks, and Connectix's Virtual PC both have new, OS X-capable versions out that I've reviewed on lowendmac.com. Take a look at the Dave 3.1 and VPC 5.0 reviews, and feedback on the reviews is always welcome!
Mac OS X Hints
http://hints.macworld.com/article.php?story=200201271106400