Exellent Rated 5 out of 5 stars

It does exactly what is must do, insert an equation in an e-mail. Earlier reviews mention the image being stored on an external server. I see the image UUEncoded embedded in my mail. So IMHO there is no server involved and the image is part of both the sent and the received mail forever.
Installation was easy. I had both Latex and Imagemagick installed. They were autodetected without a problem. I only had to add the LatexIt! button to my toolbar manually. It would have been easier if the installer had taken care of this as well.
The one bog advantage of this add-on is that the addressee doesn't have to install anything. I am just wondering if clients like Outlook don't mess up the message. I don't have Outlook and I don't know people who use Outlook _and_ recognize a mathematic formula.