First of all, The Ruby Toolbox is amazing! I no longer have to read a bunch of Ruby mailing lists just to know which tools are useful and which tools aren't. There's so much stuff already there that (out of ignorance) I thought I would have to build from scratch.
Second of all, did you know that hitting Cntl-Shift-t in Firefox (at least on my Linux box) opens up the last tab that you closed? That was a weird thing to stumble upon.