I take issue with the anonymous "tip" format. I would always prefer a short, personal email -- to me, this is much more meaningful and reflective of why I do open-source. I also think that offering monetary tips encourages tip grubbing. I've already seen a bit of this from big names in the community and, for me, its a big turnoff. I give my code away, that's what OSS is all about. Thank me by writing an email, or better yet, contributing some patches!