Why does Google have two ls?" is a question many people are asking this morning. The answer is simple. Google is celebrating it's 11th birthday. The two ls are actually two 1s.
In something of an interesting quirk Google actually displayed its 10th birthday logo on 2 September. The wisdom of Wikipedia suggests Google became a private company on the 4 September 1998. This has left some people to ask; "When exactly is Google's birthday" and others to suggest that Google with two ls is marking the search engine's birthday on the wrong date.
Google did change its logo in the same way for it's 10th birthday. Rather than having "Googlle" it displayed "Goog10".