You can protect yourself from being monitored by MS, ZoneAlarm, Adware
Also backdoor type virus's open up outbound ports to send out personal data it may collect on you or to use your machine as a SpamBot. An outbound firewall lets you decide which programs can dial out.

Bob

>>Why does a firewall need to protect outbound traffic? I thought the purpose was only to handle inbound.
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>Well, if some lovely thing like adware etc. gets into your computer it can pull data from your machine over the Internet. I like to control outbound traffic. :)
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>>>Is there really a compelling reasons to upgrade to Vista (besides eye-candy)? I don't think so. Much has been made of the security enhancements but all in all I think a properly setup Windows XP/SP2 box is just fine, but I guess its a personal choice. UAC is a huge pain and will result in users either (a) switching it off, or (b) just clicking "continue" without even reading the message. Windows Defender is no where near as good as 3rd party products. The Windows firewall is only half a firewall by protecting inbound traffic only.
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