Atheism is not a religion, but it is a world-view, and as a world-view it takes on many of the attributes of religion.
1) Seeking Converts
Atheists want everyone to believe as they do and are continuously trying to convert people to their world-view. If you don’t agree, think of Bill Maher, the late Christopher Hitchens, Richard Dawkins, that guy with the bow-tie who does kid’s shows, and all the guys on Youtube.
2) Controlling Politics
Atheists want their people in office to create policies which favour the atheistic world-view.
3) Punishing the Heretics
If you are not an atheist, you are not welcome in their society.
4) Preaching Salvation
Salvation comes through atheistic/humanistic moralism and science.
Religious people and atheists do all these things alike. This is why people will say that atheism is a religion. Sure, atheists don’t worship a super-natural being, but they do worship something. We all worship something.
Pursuit of Percipience 
1) Welcome to the religion of stamp-collecting. Or soccer. Of Walmart.
2) Most atheists I know would simply prefer religion or non-religion being no part of politics, but simply a personal decision. Nothing more, nothing less.
3) Most atheists I know are stronger defenders of religious freedom than many Christians, who only support religious freedom if it means keeping Christian privileges intact.
4) What is salvation? That’s a pretty religious term. Moral values, Happiness, etc. can come without a god, true, but what is salvation? Why do we need it?
If that lose definition of “worship” is your basis for “religion”, then, let me repeat that…
Welcome to the religion of stamp-collecting. Or soccer. Of Walmart.
Because according to your definition, all of these are religions. Ok, I don’t have a problem with that, if it means that Christianity will have as much special privileges as the local soccer club – none at all.
This is an article describing world-view, not religion.
1) Stamp collecting is not a world-view.
2) Your world-view determines your politics.
3) Your world-view determines how you want others to act and who you associate with.
4) Your world-view determines how you want society to be structured so that all people can live long, happy, and free lives (if that’s what you really want for society). Also, your world-view determines how you would structure society so that future generations can enjoy the same kind of life.
Atheism became uninteresting the day it became a “religion,” in my opinion.
Frankly, it’s incredible how “omnipotent” atheists can be thru their assumptions; somehow seeing beyond a singularity, or refusing to consider the implications of a potential “infinite universal template.”
The idea anyone would choose to “think” mankind “knows” what takes place (at this point) beyond our own solar system (much of which is derived by measuring light which emanated long before our existence) is just silly; arrogant and naïve beyond measure.
In which case, Bill Maher is a total doosh … funny …. but a doosh!
Would love to get your input on either of these links.
http://troymo.wordpress.com/2011/10/18/omg-where-are-you/
http://troymo.wordpress.com/2013/01/01/arguing-with-atheists/
Cheers!