Wallwisher vs. Corkboard
A few months ago, Risus Monkey turned me on to Corkboard. I haven't used it for gaming yet, but have been using it to keep track of some research notes on a book I am reading. Today I discovered Wallwisher. It's a lot like Corkboard, except you can customize the look of the board and can easily post photos, audio, or video (though when I posted a link to a YouTube video it didn't work). There's a character limit (160) on the Wallwisher notes, which gives Corkboard a big edge in my book, but Wallwisher does have more multimedia posting options. It also lets you customize the web address of your board, unlike Corkboard.