I don't think you need to worry, it's a "trusted" application. If you used Mail.app you'd want to give Keychain access also. EDIT: If you can still send & receive mail in Entourage without it, then leave it alone.
Here's the advice I usually give about security:
While there are no known viruses that attack Mac OS X at the present time, it is possible for spyware to get onto your Mac.
So I go to lengths to protect my user. A hosed system can be replaced but a compromised user folder is compromised forever. Along with all your important data like bank records, credit cards, ... I.e. your "identity" stolen.
The best way to avoid that is by using your built-in firewall which is industrial strength and/or a hard wired router, downloading only from "trusted" sites, installing all security updates and being careful about what you give administrative power to. It is also recommended to run day to day tasks from a non-admin account.
Don't use Limewire or any other P2P service to download your software, get it from reputable sources. In addition, always keep at least your users backed up, preferably a clone of your entire system on a separate disk. And put your sensitive passwords, bank accounts, credit card numbers in a "secure note" in a new keychain or in an encrypted folder.
If and when a Mac virus does appear it will be headline news and you can download the AV software then. If you feel you have to run an AV program I'd suggest
ClamXav a mac friendly freeware app that is very stable with OS X. It will check for known virus signatures at any rate.
Hope this helps.
-mj
Message was edited by: macjack