I'd prefer to try the wiki approach first; set up a target monthly goal for donations, for example, and keep a chart/graph of it in the corner on the front page, maybe, showing how close the site is to meeting the goal for the month, etc, and quick link where we can click to donate money here, money there. I'd most definitely donate some $$$, and I'd rather do that than have a monthly subscription....I hate monthly bills and such.
Bah!