Gamification or Game-based marketing is the new buzzword right now as exemplified by Facebook social games like Farmvilla or blogs like Mashable Follow.
Here's several concepts that have been done for productivity systems already.
Screenshots:
Chore Wars (browser)

Progress Quest (Browser/Windows Desktop/IPad) - Game addiction saver

Destruct-o-matic - (browser) Although there are lots of point based habit trackers, this one is the closest thing to really capturing what it means by gamification as opposed to rewards-based systems.

AskCourageWolf (Also on Facebook)

Slot Machine Personality Quiz - Uses bias bypassing concepts like cards rather than quizzes to obscure cheating.

E-mail game (Inbox Zero Read or Die type game)

Videos:
Epic Win (Iphone)
Noborizaka (Windows Phone 7)
Half a Minute Hero (PSP)
GTD+R - Adding colored labels to GTD Index Card type systems From: Necro DIYPlanner Topic
Links:
Free Rice (browser) - charity enhancer (note that this have been gamed already and you're not giving as much as those guys who used automation programs for this)
3rd world farmer (browser) - empathy builder (notable for being closest to Farmville's concept)
750 words (browser) - writing (although there are other writing games this one is notable for having a leaderboard)
Anuran - Not posting a screenshot cause it's deceptive. This one needs to be heard to be understood.
Google's Fashion Engine based on Like.com: image comparison engine
http://www.luxist.com/2010/11/18/the-fashion-statement-googles-fashion-engine/
What kind of a Teacher are you? (Needs Facebook to test) - Results don't just show results but link directly to advises.
http://www.facebook.com/apps/application.php?id=154514724570539
Free Leech:
Free leech means that what you download will not be counted. It is a way to build up your ratio at the site.
Most private sites will still enforce their hit and run rules on those torrents. Usually it is seed for 72 hours or until 1:1 ratio.
So don't download and not upload on those as that could get you into trouble there.
Here's several concepts that have been done for productivity systems already.
Screenshots:
Chore Wars (browser)
Progress Quest (Browser/Windows Desktop/IPad) - Game addiction saver
Destruct-o-matic - (browser) Although there are lots of point based habit trackers, this one is the closest thing to really capturing what it means by gamification as opposed to rewards-based systems.
AskCourageWolf (Also on Facebook)
Slot Machine Personality Quiz - Uses bias bypassing concepts like cards rather than quizzes to obscure cheating.
E-mail game (Inbox Zero Read or Die type game)
Videos:
Epic Win (Iphone)
Noborizaka (Windows Phone 7)
Half a Minute Hero (PSP)
GTD+R - Adding colored labels to GTD Index Card type systems From: Necro DIYPlanner Topic
Links:
Free Rice (browser) - charity enhancer (note that this have been gamed already and you're not giving as much as those guys who used automation programs for this)
3rd world farmer (browser) - empathy builder (notable for being closest to Farmville's concept)
750 words (browser) - writing (although there are other writing games this one is notable for having a leaderboard)
Anuran - Not posting a screenshot cause it's deceptive. This one needs to be heard to be understood.
Google's Fashion Engine based on Like.com: image comparison engine
http://www.luxist.com/2010/11/18/the-fashion-statement-googles-fashion-engine/
What kind of a Teacher are you? (Needs Facebook to test) - Results don't just show results but link directly to advises.
http://www.facebook.com/apps/application.php?id=154514724570539
Free Leech:
Free leech means that what you download will not be counted. It is a way to build up your ratio at the site.
Most private sites will still enforce their hit and run rules on those torrents. Usually it is seed for 72 hours or until 1:1 ratio.
So don't download and not upload on those as that could get you into trouble there.





(Not even in our theoretical assumptions because we have no idea how codes look like.)