You can also just build tip on your own locally. Go has virtually no hard dependencies other than gcc (and mercurial to get the repo, unless you pull the code some other way).
hg clone http://code.google.com/p/go
cd go/src
./make.bash
(or ./all.bash if you want to run all the unit tests)
Same holds true even on Windows if you have a local gcc like MinGW (the only notable difference is you'll execute make.bat instead of make.bash if you're in a Windows cmd shell instead of bash).
Google also distributes binaries for Linux, for me all I do is unzip the file and set up my .profile to look for go in the path it was exported in..I set this up on a per-user basis but it works fine for me.
I'm going to try it on FreeBSD.