Connect to HipChat and Slack from a single client

For those who don't care to juggle multiple native chat clients or use the web UIs, you can access both HipChat and Slack from a single, local client like Adium or Pidgin over XMPP.

Naturally, there's a bit more friction and you may miss out on some instance-specific functionality, but being able to use a single, extension-ready application for all chat (including gChat and IRC!) is nice.

Slack and HipChat provide guides to set things up.