That is not usually a viable option except for new homes, as installing ethernet in all useful rooms in a home really tears up the walls and ceilings. Some might want to use their laptop in the cr@pper, but not me, lol. It's not worth it for most. The exception would be 1 or 2 rooms, depending upon the distance and routing of the cable and location of wall jacks.
If I had my choice, I'd buy a new home with CAT-6 installed in every room. To be as secure as I can be with my current equipment, I do the following:
1) Enable WPA-TKIP and use a long random password (my router doesn't support AES or WPA2)
2) Turn off SID advertising
3) Turn off DHCP
4) Enable MAC Address filtering
5) Assign Static IP's to specific MAC addresses in ACL
That is the most secure my home wireless network can be without having to buy another more modern/advanced wireless router. I'd recommend anyone with wireless home networks do the same, though WPA2 with AES is preferred. Just my 2 cents.