File sharing security question

On my laptop with XPHome SP2, I have it set up with a couple of fully-shared
folders on my home network, for ease of transferring photos and files in
general. I usually just plug it in to the RJ-45 wired connection at home
(through router with firewall), but the wireless connection is WEP protected
for the home network. Windows firewall is enabled.

The question: If I go to the local coffee place that has free wireless
connection and connect to the internet (not sure about them using WPS), will
any other users on that wireless be able to see or access my shared folders
if they're not password protected? There is nothing particularly critical
or private in them at any time, but it would be nice to know if setting a
full-access password is a "must do" for this. Or, is that not enough?

I'm not the paranoid type, or concerned about top-level security, but don't
necessarily want someone in the coffee shop to click the network places
folder and find my workgroup and folders sitting there accessible with just
a click.

Gary