I regularly use 3-4 different computers, from time to time also guest operating systems running in virtual machines. For years I have been thinking it would be great if you could bring your current Firefox status with you to a different computer, for example between a Mac and PC.
After recently actually looking into this topic I found the new Mozilla Weave Firefox extension. It is in beta and have some bugs, but is very promising even in its current state. However, it doesn’t sync sessions.
I recently also started using the nice Dropbox service for file syncing. Dropbox has both Windows and Mac clients and works fully transparently: any file you put in the dedicated Dropbox folder on your local computer is automatically synced to the Dropbox service and from there propagated out to your other computers where you have Dropbox installed and running. As you get 2 GB of free storage that is more than plenty for storing session information.
Only thing missing now is to find where Firefox’ sessions files are stored. As I am using the excellent Session Manager Firefox extension, a quick look in the Advanced tab of its options dialog revealed that you can indeed specify where Session Manager’s session files should be stored. Change this to your local Dropbox folder and you are set! As soon as you save a session in Session Manager it will be almost instantly available on your other computers. To use them on these other computers you use the “Load session…” command in Session Manager’s menu, which in turn is found in Firefox’ Tools menu.
Have been using this setup for some weeks now, works flawlessly.