I have seen that. But, first of all, ruby 1.9 has a sharp increase in performance w.r.t. 1.8. And then, while I am no Gentoo user, I like to compile by myself all key elements that I use for developing. You learn a lot in the process. On my four-core desktop it takes less than a minute to compile Ruby. Even if I were to wait 5 minutes for compiling it on the maemo device, I believe it is time well spent.