I've never been one for April Fool's pranks, though some of my co-workers in the past have been pretty notorious (someone reversed the horizontal and vertical axes on my mouse one year - it took me ages to figure that out). While I don't play any pranks personally, I always look forward to spending a little time enjoying the pranks online.

Logging into my Gmail this morning, I discovered I could send email messages back in time! No more belated birthday messages! There are some limits, however:
You'll only be able to send email back until April 1, 2004, the day we launched Gmail. If we were to let you send an email from Gmail before Gmail existed, well, that would be like hanging out with your parents before you were born -- crazy talk.
Google is also accepting applications to colonize Mars in 2014!
Earth has issues, and it's time humanity got started on a Plan B. So, starting in 2014, Virgin founder Richard Branson and Google co-founders Larry Page and Sergey Brin will be leading hundreds of users on one of the grandest adventures in human history: Project Virgle, the first permanent human colony on Mars.
Make sure you fill out your application. This is my result:"Congratulations -- you are ideally suited to be a Virgle Pioneer; so ideally so, in fact, that one wonders why you aren't already living on a remote South Pacific island, serving as a biosphere test subject, washing dishes at a North Pole research station during the depths of winter or writing a highly intelligent, articulate political blog."

Blogger has also announced a revolutionary new blog service:
Save your readers time and effort. We’ll automatically extract the most relevant sentence from your post for the index page, along with any necessary ellipsis. We'll also put some words in bold!
Sounds like something I could use...

I'm sure there will be a more comprehensive roundup in the blogosphere later this week, but here's my favorite so far:

World of Warcraft announces a new hero class for Wrath of the Lich King - the Bard!
Armed with a trusty axe, killer riffs, and a ton of attitude, the guitar-wielding bard is the second hero class to be introduced in the upcoming Wrath of the Lich King expansion for World of Warcraft.
Every game needs more cowbell!

Update: I can't resist!
For more complete April Fools lists, see April Fool's Day on the Web