Yes, Samba. Go to the Finder Go menu and select "Connect To Server". Enter something like this into the Address field:
smb://computername/sharename
where computername is the name of your computer as shown under System Properties->Network->Full computer name. Be wary: the name is case-sensitive and the name given here and the NetBIOS name may not be the correct case. To verify the name, go to My Network Connections and see what your computer name shows there for the case that will work using SMB.
Sharename is the name of the drive or folder you have shared on your Windows PC. No spaces allowed.
This is a one-way connection (unlike Dave); you can only see Windows files on the Mac and not vice versa.
Good luck,
Kuroyume
Addendum: Windows file/print sharing must be enabled for the connection that you'll be using. Also, you may have to wait until the Mac connection establishes its IP address and mask from the DHCP server depending upon your setup. Unless you set these up manually on both machines, they'll negotiate addresses (which can take a minute or two). When you see that the connection has an IP address (Mac: System Preferences->Network), you've got the connection and continue with the "Connect to Server".