You guys need Fon
However Ploum in the comments is right about being afraid of the morons that are proud to say that they used the open wifi of their neighbor to download movies and they took away all of the monthly 15Go limit in a few days !
Thats why you should use Fon. it gives you both bandwith limitation,
security, logging and other things. You get to see who has been using your AP , for how long, how frequent etc .. You can Limit the bandwith someone uses. etc. And because off course you choose to be a Linus, you get to surf on other peoples connections when roaming around.
What else would you be running on a Linksys ?