OS X Server Log In

My iMac, a great machine, it has OS X Server 10.4.10. I use it as more of a workstation than server, mainly because I like to tinker with the little gadgets and cool things server edition has. Well I'd like to be able to log in by clicking my name rather than typing in my user name and password. I know that this isn't critical but I'd prefer it. As it would be called in the options, List of users. In the options for this, there is this option but it is grayed out. I was wondering if OS X server has anything like the Administrative Tools, Local Security Policy that Windows NT has that would prevent me from changing this option. Any ideas, anyone? Thank you TSG community.