I'm going to mostly ignore Rails Rumble entries till we see which (if any) stick.
- Rubytune - Sharp guys who will help you troubleshoot performance in your Rails application.
- Capistrano-Mailgun - Send deployment notifications via Mailgun API.
- newrelic-rake released - Gem to add New Relic instrumentation to rake tasks.
- HTTPS Everywhere - Firefox/Chrome addon from EFF devoted to making sure you get as much benefit from secure connections as possible.