If you even have the slightest interest in Powershell, then check out PowerGUI. PowerGUI is a REALLY nice extensible wrapper around Powershell. You can learn a lot from the script source that's included in the product and there's a TON of exchange 2007 stuff that you can do from PowerGUI that's hard to do from the existing management tools, or only implemented in Powershell.
Best bit - it's free! Check out http://www.powergui.org/index.jspa for really nice forums and a free download. You may want to apply what you're learning about PowerShell and exchange 2000/2003 and extend PowerGUI to suit your own admin needs.