I am finally taking the time to update my toolbar extension tutorial for Firefox. The new version will feature all of the great new development improvements featured in Firefox 1.5 (development has gotten a whole lot easier). In updating the tutorial, I've already learned a few things that I didn't already know. For example, extensions no longer need to make use of GUID's; the format extensionname@yoursite.com can be used instead. That change alone makes things so much easier to understand.
I have no idea when the updated tutorial will open up to you, the reader, but it will hopefully be sometime soon. I'm currently working on rewriting section 2 (Creating the Framework). It just so happens to be the section that requires the most revamping. As a result of the tutorial focusing on Firefox 1.5, I'll be throwing support for Firefox 1.0.x to the wind. My decision to do so is based on the new development features provided by 1.5. They alone outweigh the loss of 1.0.x support in my eyes; hopefully you agree on that point as well.