[tocomment]

Question I've been wondering. What happens to lost bitcoins? Say your hard drive dies and you didn't have a backup.

Are those coins out of circulation forever? Will this gradually decrease the supply of bitcoins?

[nacker]

Yes. Gone forever.

https://bitcointalk.org/index.php?topic=109117.0

[wglb]

Or, in technical terms, Clementine.