A Euro sign, €,  in Google Docs can be inserted with Alt+0128 [Press and hold the Alt-key on the keyboard and then type 0128 on the numeric keypad, meaning the extra numbers on the right-side of many keyboards.

Any tips for Euro signs on other platforms/keyboards are welcome and will be added here..

Alt+0128 also works in:

Notepad (Dutch: Kladblok) in Windows

Word?

Adobe Dreamweaver 5 (bot code-view and design-view)

Any good links to other Alt-shortcuts or  ASCII-codes that actually work?