Networking Question. Please help

[flyhigh]

I have a windows XP desktop PC as my main computer with a Linksys WRT54GS wifi router. I currently have a home network for a Vista laptop and of course my Touch Pro where both can share the internet as well as file sharing. Everything is working great but my needs have changed. I will be having guests and I want them to be able to access the internet over my wifi but I want to restrict them to only internet and not have access to file sharing. If I give them my network password, they have access to everything so how do I restrict them to just the internet. I'm guessing I have to limit file sharing to specific MAC addresses but how does that affect my TP and where do I fing my TP's MAC address. I realize this question goes beyond the scope of this forum a bit but but keeping my TP on my network for file sharing is critical.