<Edited to get to the damn point already and make it more clear how not about white people this is, except to the extent we can be of some small service/comfort/relief/whatever>.
Other than protesting, donating, and finding ways to amplify the smart voices of people of color, here's one thing I think white allies should be doing right now: dealing with Facebook racists. Because all the people of color I know say they just CAN'T with that shit right now, but I can. And I'm an extra sneaky weapon because I'm white. Maybe don't start with like the craziest ones first, but I figured what if instead of defriending someone for their Fox News post, you figure out what their weak spot is — maybe they're super sensitive about being Polish or maybe they have an austistic niece or maybe (god forbid) they've been sexually assaulted or whatever (real or perceived) hardship they or their loved one might face. And then instead of calling them an idiot, you say, hey, you are such a great person. I can't believe this is what you think. Here are a couple of ways you might identify with what black people in America are feeling, because you get the short end of the stick too, right? And isn't that sad and hard? And you just pretend that you're mostly on their side except for this one little thing so that they write back to you. I mean I just basically agreed that the portrayal of Italians on the Jersey Shore was equivalent to cops killing black men and boys so that he would feel like I took his concerns seriously. And then you start, like the sweet "nonthreatening" little white girl you are, very gently taking apart their bullshit. And then you keep going until you exhaust them. I mean, I have the patience and the privilege to do this right now. And I think it's paying off/changing some minds! (I got at least one person to recant!) Or at least getting them to shut up so the facebook feeds of others aren't clogged with this trash.
So, fellow whites. Go do the inside job that you are uniquely suited to do right now.