I'm very excited about the tool tracking. You nailed with the thought that people do borrow and never return them just like books/dvds. Great that it can be hidden for folks who aren't into that.

I'll also throw my vote in for the idea of .Mac syncing of my library from laptop to desktop.

I'll also state that I would be willing to pay an additional fee for an iPhone app that would let me use the camera on my phone to scan bar codes and then sync all of the stuff I scanned on the phone back into my main library. I would definitely pay for the ability to enter my entire book library w/o having to cart them in front of my computer or having to buy a dedicated scanning gun.