Polluting Gentoo

Let it be noted that this is the first time that I polute my Gentoo box. That is, by installing something with ./configure && make && make install and stuff. I did it as I was trying to make GmailFS work here, through the instructions on this website (pt-BR). Apparently, it didn't, and now I don't even know how to remove the "low-level" installation garbage I ended up with. Does anyone?