i agree that samba is the best way to transfer files if you can get it working. one other option that i have used is the swiss file knife (SFK). SFK is a really small utility with lots of functionality including an ftp server. assuming your guest has network access, you can install SFK on host and guest, and ftp files back and forth. this method is not as convenient as using a samba server. if you're moving a lot of files at once, it's a pain. you pretty much have to pack them in a zip archive so you can just move one file. but the main advantage of this method is it's really easy to set it up. if samba isn't "just working out of the box", it's nice to have another option until you get samba working. this link explains the details:

http://stahlforce.com/dev/index.php?tool=vmftp