I just gave an answer to a similar question here:
Can I use my Ubuntu desktop to cross-compile the GO language environment for my Pi?
NB. I'm not Frepa ;)
To summarize, yes it is, but building a cross-compiler is not a trivial task for most people; I recently used crosstool-NG to do it which A) made the procedure pretty painless, B) produced a c/c++ compiler that works to compile executables for the pi.
If you just want this to build your own stuff then I do recommend it if the caveats I mentioned there about use of autotools and pkg-config do not apply or you are willing to deal with the hassles to make that happen (dealing with those hassles may take you longer than just compiling on the pi, so...).
Crosstool-ng can produce a basic environment in which you can compile programs that rely on the standard libraries + POSIX threading (that's what I tested successfully). Beyond that, you have to build any support libraries you use (sqlite, curl, ncurses, etc.) in that environment first too.