Unicode

This is the Euro sign as €:

€

This is the Euro sign as the actual character:

€

This is a music symbol that doesn't have a font:

𝅘𝅥𝅮

This is an arrow:

⬀

You can even link to a page with Unicode characters in the title: €

Some Dingbats:

❋ ✰ ✠ ✡ ✔