I'm sure there are many other ways of doing this, but ... after hours of frustration trying to get a new Toshiba laptop running WinXP Home Edition to see our Linux Server and my OS X Ti-Book on our office network through the Network Neighborhood, I finally called in a UNIX guru friend of mine who suggested the following.
Open the Registry on the Windows machine (just type "regedit" from the "Run" command"). Then adjust the following Entry:
\HKEY_LOCAL_MACHINE \ SYSTEM \ CurrentControlSet \ Services \ lanmanworkstation \ parameters \ enableplaintextpasswordChange the default "Value Data" field from 0 to 1. Restart Windows and Voila! The Linux and OS X machines show up in the Windows network neighborhood.
Mac OS X Hints