The question was asked when Synergy was hard to install on a Mac, with 1.4.5 it's now easier:
This is also explained in the user guide (found on the help page).
For the old 1.3 version:
step 2, type > pwd(enter) - this will well you your working path
step 3, i had to use > sudo su(enter) then type in your regular password (your prompt changes after this)
step 4 once you are sure you are in the correct folder you can type cp synergy* /user/bin(enter)
or first type ls synergy*(enter) and you should see a list of the files that you are copying to the other location e.g.
mac:synergy-1.4.3-MacOSX106-Universal user$ ls synergy*
synergy.conf.example synergyc synergys