Two Cool Time Wasting Web Thingies

I’ve been swamped with BlawgThink stuff lately, but finally spent the morning catching up on some of my feed reading.  I came across these two cool sites that are worth a brief look:

The first is an online optical illusion.  I’d love to figure out how to use this in a presentation.

The second is an real-time list of things people are tagging with De.licio.us.  Very cool and strangely addicting.