I block ads period. Now if I traffic a website regularly I'll be more then happy to donate a dollar every now and then. If you can detect your ads aren't being displayed then put up a donation box in it's place. Oh and setting set donations doesn't work as you'll always get more money from people donating $1 then from people who donated $5 or more unless you're really lucky. I've donated to several people for their software and I'd be happy to donate a little to good websites. But it's a very bad idea to block people blocking advertising because those people tend to be more savvy technically speaking, more likely to post links to your site among other things, visitors you don't want to lose.