For nearly a month, we've needled gay Hollywood to contribute to the "No on Prop 8" cause that, for a while, seemed to be the exclusive domain of straight allies like Steven Spielberg and Brad Pitt. Most visibly MIA was Ellen DeGeneres, whose marriage this summer to actress Portia De Rossi should have given her even more reasons to fight Prop 8, which is designed to take away marriage rights awarded to same-sex couples in California. Now, finally, DeGeneres has stepped up to the plate, donating $100,000 so that the "No on Prop 8" campaign can air a new ad DeGeneres has recorded about how the proposition affects her personally. Props must be paid. The ad, after the jump: