Wireless Internet Security Guidline

"Don't use WEP. WEP is the antithesis of security, giving a false sense, despite the fact that any trained monkey with a laptop can break into your network.

Mac filtering? Pointless, anybody who wants to get in can get around that no problem.
The best security advice I can give is: Use cables.

That's not always possible, though, so just use the best encryption both your router and hardware connecting to it supports (Some MID from Archos? Mine only does WEP!) and use that. Hide your SSID, and change the key if it came with a default. Nothing I've suggested is infallible, far from it, so just hope nobody really wants into your network. If there's another nearby connection not as well secured as your own, most people would use that instead. Security by obscurity ain't great, but in a world where we're transmitting an internet connection over the air, it's better than nothing."