When I visit Google search there isn’t a banner begging me for money that will be piped into Google Wave, Buzz, or some other unrelated venture.

No, instead your personal data is sold to fund Google Wave, Buzz, or some unrelated venture.

Would you prefer wikimedia shift into selling user data and putting advertisements? If not, then donate.

> "Would you prefer wikimedia shift into selling user data and putting advertisements? If not, then donate."

I'm sure you didn't intend it this way, but this phrasing sounds like a threat of some sort, blackmail.

That’s a false dichotomy. Another option is to allow donations that are ring fenced for the project or projects I care about.

I would strongly argue that ring fencing is a very bad idea. We want to give opportunity for successful orgs to try new things and fail. This is why companies use some of their profits to try new things (such as Google Wave, but also such as Gmail). Wikimedia foundation, since it does not generate much revenue outside of donations, must necessarily use donations to try new things, even if they turn out to be failures/not needed.