I'm giving a presentation on Learning Object Repositories tomorrow as part of Faculty Technology Days. I've been madly whipping up a whiz bang Keynote presentation for it, and it's pretty much done. It's written in a newbie "what is a learning object" perspective, and builds from there.
I've posted it online here (pdf) and here (mov). The PDF version needs some tweaking (lines are white on a white background. It looks awesome on screen, but I switched the background to white for PDF and print, and lines don't show up. Use your imagination for now…)