You probably already know that securing your Wi-Fi network with WEP encryption is barely better than none at all. But even the vastly superior WPA is surprisingly vulnerable to intrusion, particularly when short and/or dictionary-based passphrases are used.
To maximize the security on your wireless network, stick with WPA2; it uses AES encryption, which is far stronger than the TKIP (Temporal Key Integrity Protocol) method commonly used by WPA. Be aware of two caveats, though: first, some non-PC Wi-Fi devices may not support WPA2 (firmware updates may address this). Also, WPA2 consumes more computational power than WPA, so it could degrade the speed of your wireless network when used with older access points and/or PCs.