Coworker Coffee - Coffee with a different coworker each week
Lunchclub - Curated 1:1 professional connections
Serendipity - Serendipity is a PHP-powered weblog engine which gives the user an easy way to maintain a blog.
Twine - Twine is an open-source tool for telling interactive, nonlinear stories.
Lunch Roulette - Collaboration by grouping coworkers randomly for lunch.
LetsLunch - Do more with your lunch hour. Meet new people.