[wlesieutre]

HipChat uses parens for this, with (thumbsup) turning into a thumbs up icon even if you're communicating through the IRC bridge. It's a bit weird when you're using parentheses for a parenthetical and it pops up the emoticon search, but you get used to it.

[blacksmith_tb]

The Slack equivalent, which wraps the keyword with colons, :+1: is less likely to happen on accident. I am surprised HipChat went with parentheses, honestly, but maybe they felt they were too subtle for mobile users (I like them, myself). It is nice to have a text-only method of mapping to emoji, though.

[wlesieutre]

For extra fun you can add your own in-joke shortcuts within your organization.