I am currently having problems with sound not muting when headphones are plugged in so this may well be one of the topics I cover shortly.
I did however manage to get my new mouse, the saitek cyborg R.A.T.5 running in Linux.
There is a problem when you first plug it in that means you have to click the change mode button every second click but I managed to find a fix that should also work for the R.A.T.3 and the R.A.T.7.
Here are pictures of the R.A.T.3 ,5 & 7 for those who haven't seen them:
The R.A.T.3:

The R.A.T.5:

The R.A.T.7:

(there is also a R.A.T.9 but I can't confirm that the fix works for it)
The fix is quite simple.
It does rely on Xmodmap.
Here are instructions using sudo. If you have a root account ommit sudo and run them as root.
First you need to edit the Xmodmap file with your favourite editor. I prefer vim. the Xmodmap file should be here:
/etc/X11/Xmodmap so to edit with vim I typed:
bash$ sudo vim /etc/X11/Xmodmap If you are unused to vim I recommend nano as a good alternative:
bash$ sudo nano /etc/X11/Xmodmap All the file has to contain is:
pointer = 1 2 3 4 5 6 7 8 9 10 11 12 0 0 0 If there is already information in your Xmodmap I recommend putting this at the start.
You can then restart X or your computer and it should work without a problem.