Not so much nervous myself, maybe if we actually get an interview maybe my nerves will kick in then. ;)

This sounds kind of like http://www.chatterous.com/ to me.

actually it sounds like ididwork to me

yeah it does sound like ididwork but I can see why TC went crazy for Yammer. Yammer sold its self as a communication tool while ididwork sold itself as a sort of Rescue Time/punch card/productivity tool.

In the end Yammer looks fun while ididwork looks scary.

A few YC site logos (tipjoy, reddit for example) appear in this mosaic of the world.

I've made a few startups and I try to be real careful when picking logos/images/etc. How does changing a 'major brand' icon like effect things?

I used this a few months ago it was great.