Been "playing" with Linux off and on for the past 11 years, never really doing anything with it, other then just getting comfy with the CLI. Started off with slackware, didn't know what to do with it so I went back to Windows (gasp!). Played with Solaris on an actual Sparc cpu (50 MHz! 4 gb scsi drives in a cluster. Good times) at school - my teacher had some cool stuff back then.
So fast forward to 2005, and I decide - I'm going to learn Linux. And I'm still learning. I convinced my boss to let me turn an old workstation into a Linux server (Fedora Core 4), and then, compiled EVERYTHING from source. I wish I read some more before doing that, coming from Windows you almost always want to run the latest and greatest version (which is what I was taught). Took me 2 years before I found out about the power of yum ... lol.
So what I can do quite comfortably (with a generous dose of google-fu and perusing example config files) is do a generic LAMP setup, using virtual hosts (we run 5 web sites @ work). We use CentOS 5 now, in multiple virtual machines (VMware 3 server license, using ESXi on 2 poweredge 2950's (2*2.0ghz quad core xeons, 32 gb ram each) with an (Windows based) iscsi backend.
And that's about it. Oh and that yum is my friend.
We are an MS "shop" but I try to squeeze in some Linux where I can, when I can ... because I can.
But I have some questions, and I want to do more - I just don't know what else I CAN do. Currently playing with the fog project, trying to clone Linux (Windows worked better in this setup).
Mahalo, and I look forward to asking many (many) questions.