That's awesome if you would like to donate! If everyone who used these proxies donated $5, that would be more than enough to keep these servers online, and possibly to upgrade to more reliable hosts (some of the ones I'm with now don't have an SLA, and are down more than I'd like).
If you make a donation, please let me know what your preferred proxy is. I'll make sure that if I need to retire a proxy due to lack of funds that I don't pick yours!