This is mainly a reference for me, but might come in handy for other folks looking for oddball HTML entities and things.

Musical Entities (who knew?!)

♩ ♩
♪ ♪
♫ ♫
♬ ♬
♭ ♭
♮ ♮
♯ ♯

Other Strange Entities

→ → The Pirate's Tag! Shows a nice little arrow (also has ← for left)
» » Nice little double arrow (« for left arrows)
· nice · little · dot · for · separation
— — big long dash

Other Fun Tags

will indent some text like this for when you wanna quote someone

will scroll some text Abbreviation tag that shows a tooltip when someone hovers over GMC

Here's a bunch of others at the W3C, but they don't have examples