As described in this topic: A guide to sharing bookmarks, macros and scripts, you can now save your FireFox macros and scripts as a URL and share it or run it yourself.
The following FireFox add-on makes it possible to start bookmarks using a shortcut. We checked it and it works very well with iMacros bookmarks. Now, instead of opening iMacros toolbar and starting a macro with a click, you can create a bookmark for it and run it with a shortcut.
Here is the add-on:
SiteLauncher 1.6.4
Best regards,