Can OS X dump cores in the working directory instead of /cores?

I finally figured this out. It turns out that this is a kernel parameter controlled by sysctl. You can set this on a per shell basis to dump in the current working directory with:

sysctl -w kern.corefile=core.%P

Since I never wanted my core dumps to end up in /cores, but always in the current directory, I added this plist to /Library/LaunchDaemons/:

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>sysctl</string>
    <key>ProgramArguments</key>
    <array>
        <string>/usr/sbin/sysctl</string>
        <string>-w</string>
        <string>kern.corefile=core.%P</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

UPDATE:

Since I wrote this, it looks like the sysctl command changed. I've updated the examples above, but if you were previously using kern.core_pattern, that doesn't work anymore.