October 31 Update: Here is a list of those who have already surpassed the 2011-in-2011 challenge goal.
October 24 Update: The first certificates will be mailed out in early November. However, keep on observing as we'll continue to mail the certificates until the end of the challenge on December 31.
As part of the 2011 Centennial Celebration we have come up with some "observer challenges" we hope you will find interesting, fun and well...challenging! There is no specific scientific purpose behind these challenges. They are meant to commemorate our 100 years as an organization. Most of all, they are meant to be fun and we hope they will encourage you to participate, or increase your participation, in variable star observing. If you happen to learn or discover something new along the way, consider it a bonus!
For just the week of 10-15 January, 2011 we are holding a contest to determine when the AAVSO International Database will get to 20,000,000 observations! Can you predict when that will happen? Show us your prophetic powers! Enter and see details here !
See who has met the challenge already here. 
The object of this challenge is to observe 100 different variable stars in 100 days.
The challenge will run from January 1, 2011 to December 31, 2011.
This challenge is open to visual and CCD observers.
The stars must be known variables with AUIDs in VSX .
We prefer you use AAVSO comparison star charts plotted from VSP .
You can start the challenge at any time in the calendar year. Progress will be checked automatically. There is nothing for you to do but observe as many variables as you can as quickly as you can. Beginning on day 101 of 2011 (Monday, April 11) we will begin notifying observers who have completed the challenge.
Periodic notification is sent via e-mail to observers letting them know of their current progress in the challenge.
Everyone who completes the challenge will be given a certificate. These will be awarded at the fall 2011 meeting in Woburn, Mass. If you can't attend, yours will be mailed to you.
Tips for getting organized-
Select the stars you will try to observe well in advance.
Pick more than 100 so you will be prepared for the unexpected.
Select stars that will be above the horizon at the time of night you observe for the hundred day window you have decided to attempt.
Select stars with good sequences. It will make estimating the magnitude much easier.
Select stars that are bright enough for you to see with your instrument. It will make this a lot more fun if you don't have too many 'fainter than' observations.
Use the lists of program stars  available on the LPV Section website for potential targets.
You can also use the CV Circular  as a list of potential targets to choose from.
Learn how to search VSX  for potential variables to observe.
This observing challenge is strictly for visual observers.
The rules are simple. Make 2011 observations or more between January 1, 2011 and December 31, 2011 and you will receive a certificate and web badge like the 100 Stars in 100 Days Challenge winners receive.
When you have reached 1911 observations an email message will be sent to you encouraging you to complete the challenge before the centennial year is over. "C'mon Dave, only 100 more to go. You can do it!"
If you have never made 2000 observations in a year before, this just might be the extra motivation to put you over the top!